Marks v Coles Supermarkets - [2020] WADC 36

JURISDICTION : DISTRICT COURT OF WESTERN AUSTRALIA
IN CIVIL

LOCATION:   PERTH
CITATION:   MARKS -v- COLES SUPERMARKETS [2020] WADC 36
CORAM:   GETHING DCJ
HEARD:   17 FEBRUARY 2020
DELIVERED          :   20 MARCH 2020
FILE NO/S:   APP 58 of 2019
BETWEEN:   SHARON CHRISTINE MARKS
Appellant
AND
COLES SUPERMARKETS
Respondent

ON APPEAL FROM:
Jurisdiction              :   WORKERS' COMPENSATION ARBITRATION SERVICE WA
Coram:   ARBITRATOR STANTON
File Number            :   A515702

Catchwords:

Workers' compensation - Appeal from Arbitrator - Whether error of law in applying the principle in Jones v Dunkel - Whether grounds of appeal challenging factual findings involved errors of law - Whether decision should be set aside on the ground of a reasonable apprehension of bias

Legislation:

Workers' Compensation and Injury Management Act 1981 (WA), s 3, s 5, s 188, s 213

Result:

Leave to appeal allowed
Appeal dismissed

Representation:

Counsel:

Appellant	:	Mr B L Nugawela
Respondent	:	Mr R D McCabe

Solicitors:

Appellant	:	Eureka Lawyers
Respondent	:	Kott Gunning

Case(s) referred to in decision(s):

Apache Northwest Pty Ltd v Agostini [No 2] [2009] WASCA 231
Atanasoka v Inghams Enterprises Pty Ltd [2004] WASCA 17
Australian Broadcasting Tribunal v Bond [1990] HCA 33; (1990) 170 CLR 321
Azzopardi v Tasman UEB Industries Ltd (1985) 4 NSWLR 139
Badran v Public Transport Authority of Western Australia [2017] WASCA 28
Beer v Duracraft Pty Ltd [2004] WASCA 192
BHP Billiton Iron Ore Pty Ltd v Brady [2008] WASCA 250
BHP Billiton Iron Ore Pty Ltd v Treby [2018] WASCA 60
Blenkinsop v Holland [2018] WADC 146
Briginshaw v Briginshaw [1938] HCA 34; (1938) 60 CLR 336
Cape Australia Holdings Pty Ltd v Burridge [2019] WADC 105
Caratti v Mammoth Investments Pty Ltd (No 2) [2018] WASCA 6
Commissioner of the Australian Federal Police v Courtenay Investments Ltd [2016] WASCA 194
De Alwis v The State of Western Australia [No 2] [2015] WASCA 42
Duke Group Ltd (in liq) v Pilmer (1998) 27 ACSR 1
East Metropolitan Health Service v Martin [2017] WASCA 7
Eccles v Koolan Iron Ore Pty Ltd (No 3) [2013] WASC 418
Engine Protection Equipment Pty Ltd v Miller [2018] WASCA 55
Erceg v Galati Nominees Pty Ltd [2016] WASCA 112
FAI General Insurance Co Ltd v Goulding [2004] WASCA 167
Fox v Percy [2003] HCA 22; (2003) 214 CLR 118
Ghazal v Government Insurance Office (NSW) (1992) 29 NSWLR 336
Hewett v Medical Board of Western Australia [2004] WASCA 170
International Finance Trust Co Ltd v New South Wales Crime Commission [2009] HCA 49; (2009) 240 CLR 319
Jenkins v Western Australian Department of Training [1999] WASCA 199
Johnson v Johnson [2000] HCA 48; (2000) 201 CLR 488
Jones v Dunkel [1959] HCA 8; (1959) 101 CLR 298
Jones v Ramsay Health Care Pty Ltd [2019] WADC 97
Jones v Sutherland Shire Council [1979] 2 NSWLR 206
Knell v QZV Pty Ltd [2020] WASCA 23
Kuhl v Zurich Financial Services Ltd [2011] HCA 11; (2011) 243 CLR 316
Malec JC Hutton Pty Ltd [1990] HCA 20; (1990) 169 CLR 638
Manonai v Burns [2011] WASCA 165
Military Rehabilitation and Compensation Commission v May [2016] HCA 19; (2016) 257 CLR 468
MTI v SUL [No 2] [2012] WASCA 87
Ogden Industries Pty Ltd v Lucas [1967] HCA 30
Pacific Industrial Co v Jakovljevic [2008] WASCA 60
Paric v John Holland Constructions Pty Ltd [1985] HCA 58; (1985) 62 ALR 85
Paridis v Settlement Agents Supervisory Board [2007] WASCA 97
Payne v Parker [1976] 1 NSWLR 191
Pollock v Wellington (1996) 15 WAR 1
R v Watson; Ex parte Armstrong [1976] HCA 39; (1976) 136 CLR 248
Re Refugee Review Tribunal; Ex parte Aala [2000] HCA 57; (2000) 204 CLR 82
Re Warden P Roth; Ex Parte Cazaly Iron Ore Pty Ltd [No 2] [2011] WASC 343
Robinson Helicopter Company Inc v McDermott [2016] HCA 22; (2016) 331 ALR 550
Rowe v Stoltze [2013] WASCA 92
RPS v The Queen [2000] HCA 3; (2000) 199 CLR 620
Smart v Albuquerque [2011] WASCA 231
Sotico Pty Ltd v Wilson [2007] WASCA 112
Spence v Demasi (1988) 48 SASR 536
Suleski v Pilbara Iron Company (Services) Pty Ltd [2018] WASCA 147
Summit Homes v Lucev (1996) 16 WAR 566
Swick Nominees Pty Ltd t/as Swick Drilling Australia v Norncott Pty Ltd [No 3] [2013] WASC 173
Town of Mosman Park v Tait [2005] WASCA 124
Velez Pty Ltd v Tudor [2011] WASCA 218
Waite v Alcoa of Australia Ltd [2018] WADC 147
Waite v Alcoa of Australia Ltd [2020] WASCA 1
Woodley v Woodley [2018] WASCA 149

GETHING DCJ:

The appellant, Sharon Marks (Appellant), worked part-time for the respondent, Coles Supermarkets (Respondent), at its Gosnells shop for a period of approximately three years prior to 3 November 2017. That day she was certified as being unfit for work due to issues with her right elbow, wrist, shoulder and neck.[1] Shortly afterwards she ceased work with the Respondent, and has not worked for it since.[2] The Appellant subsequently underwent surgery for her neck issues, following which her symptoms substantially resolved.
[1] I will refer to documents in the appellant's appeal book by the reference 'AAB #': AAB 172, 285.
[2] AAB 212 - 213.
The Appellant sought compensation for a neck injury. She says that the injury arose out of an incident at work on 12 September 2017 in which she experienced pain and altered sensations in her right hand, wrist and elbow when she was closing Ziploc seals on bags containing chickens. She says that the symptoms of pain in her right arm, wrist and hand worsened throughout the remainder of September and October 2017 causing her to seek medical advice.
The Respondent disputed the claim on the basis that the Appellant's injury was not work related. Rather, it contends that it was her activities outside of work, specifically an episode of gardening, which rendered her pre-existing degenerative spinal condition symptomatic, and that any symptoms she experienced at work were merely a manifestation of a non-compensable injury.
The dispute progressed to arbitration. The Arbitrator (Arbitrator) dismissed the Appellant's application for compensation on the basis that she had not discharged the burden of proof on her to show that she suffered an injury as defined in Workers' Compensation and Injury Management Act 1981 (WA) (WCIMA) s 5(1) (Decision). The Arbitrator published written reasons for the Decision on 18 June 2019.
The Appellant has appealed the Decision to the District Court.
For the reasons which follow the Appellant should be granted leave to appeal, but the appeal should be dismissed.

Arbitrator's Decision

The Arbitrator commenced by stating that the Appellant bore the onus of proving on the balance of probabilities that:[3]
(a)she suffered a personal injury by accident arising out of or in the course of her employment with the Respondent or whilst acting under the Respondent's instructions (being an 'injury' as defined in WCIMA s 5(1)(a)); or
(b)her employment with the Respondent was a contributing factor, to a significant degree, to a recurrence, aggravation or acceleration of any pre-existing disease (being an 'injury' as defined in WCIMA s 5(1)(d)).
[3] Decision [17].
The Appellant gave evidence. The Arbitrator went through the evidence of the Appellant closely, including an analysis of inconsistent statements relied on by the Respondent. The Arbitrator commented adversely on the Appellant's credibility:[4]
Mrs Marks was not a straight-forward historian in relation to relevant matters. Her evidence was inconsistent, and in some respects nonsensical. My findings set out below detail specific matters in respect of which I have found Mrs Marks' evidence to be unreliable.
[4] Decision [161].
The Respondent led evidence from three of the Appellant's work colleagues, Nithya Arunkmar, Narelle Jones and Louisa Bozanich. Their evidence went to the timing of the onset of various symptoms experienced by the Appellant (as reported to them), her statements as to the cause of these symptoms and the assistance which they gave her at work from time to time. They were cross-examined, among other things, as to whether they had discussions between each other on their evidence. The only admission elicited was from Ms Bozanich who said that she had discussed the timing of the onset of the Appellant's symptoms with Nicole Ladd, a fourth work colleague.[5] Although Ms Ladd had provided a statement, she was not available for the trial, and the Arbitrator placed no reliance on her statement.[6] In the end, the Arbitrator preferred the evidence of the Appellant over her colleagues as to her recollection of the events of the weekend on which she was gardening and experienced symptoms, and found this to be the weekend of 9 and 10 September 2017.[7]
[5] Decision [163] - [164].
[6] Decision [166].
[7] Decision [186].
There is one aspect of the evidence of Ms Arunkumar's evidence which is in issue in the appeal, so it is necessary to refer to her evidence in some detail. The issue is the timing of an incident in which she bandaged the elbow of the Appellant. The Arbitrator summarised the evidence of Ms Arunkumar in the following terms:[8]
[8] Decision [50] - [60].
Nithya Arunkumar was a Deli Team Member at Coles Gosnells.
Both Mrs Marks and Ms Arunkumar gave evidence that they worked together once per week. Ms Arunkumar did however state that there may have been weeks where they were rostered together twice.
Ms Arunkumar made a signed note on 13 November 2017 as follows:
'Between first to second week of October 17 Sharon [Mrs Marks] informed me during a casual conversation that she hurt wrist while doing gardening at home'.
Mrs Arunkumar was guessing as to the timing of this conversation - when pressed about the matter she thought the conversation occurred in the first or second week of October 2017 because she reasoned that the gardening in question, the planting of roses, would have happened in spring.
Irrespective of the month in which the conversation occurred, Ms Arunkumar said that the conversation (and the bandaging referred to below) would have occurred at the start of the shift, at about midday, on either a Monday or Tuesday.
In her statement Ms Arunkumar said that during her conversation with Mrs Marks about Mrs Marks' pain, Mrs Marks said that she had hurt her elbow while gardening, and that she had been doing a lot of mulching over the weekend.
During cross examination, Mrs Marks initially disputed that she said to Ms Arunkumar that she hurt her elbow whilst gardening and that she had been doing a lot of mulching over the weekend, but Mrs Marks immediately followed that denial with the statement; 'possibly the mulching but not the elbow'.
Ms Arunkumar stated that she recalled getting the bandage from the first aid box at Mrs Marks' request. Ms Arunkumar stated that she bandaged Mrs Marks' elbow.
Mrs Marks agreed that Ms Arunkumar helped Mrs Marks wrap her elbow with a bandage.
Mrs Marks made no reference at all to this interaction with Ms Arunkumar in either of her statements. Mrs Marks was questioned as to why she did not mention the bandaging in her statements, and she responded that she did not know.
Ms Arunkumar stated that prior to the shift when Mrs Marks complained of elbow pain and required the bandage, Mrs Marks had not complained of pain or difficulty with any of her duties, and Mrs Marks agreed with that evidence.
The Arbitrator found that the bandaging incident occurred on 11 or 12 September 2017:[9]
Mrs Marks' complaint to Ms Arunkumar about her pain, her reference to gardening and her request that Ms Arunkumar assist her to bandage her elbow occurred soon after Mrs Marks returned to work following the weekend spent gardening. Ms Arunkumar estimates that this conversation occurred early in October 2017.
…
I find that Mrs Marks complained to each of Ms Arunkumar, Ms Jones and Ms Bozanich about symptoms involving her arm which she thought may be related to gardening on a previous weekend. I find that those complaints were first made during the week immediately following Mrs Marks undertaking gardening.
…
I find that Ms Arunkumar's bandaging of Mrs Marks' elbow occurred at the start of a shift, before any work, including any sealing of chicken bags, had been performed by Mrs Marks. This demonstrates that if the pain related to any activity, it was likely to be the gardening Mrs Marks had done over the weekend rather than any activity performed at work. I find that Mrs Marks deliberately left out of her statement any reference to Ms Arunkumar at all, including any reference to Ms Arunkumar bandaging her elbow, in an effort to portray that she was asymptomatic on arrival at work after the weekend spent gardening.
…
I find that when Mrs Marks was gardening on 9 September 2017 she experienced symptoms of cervical radiculopathy which persisted until she had undergone surgery. I find that those symptoms had progressed to her elbow at the point of her return to work after the weekend of 9 and 10 September 2017 such that she asked Ms Arunkumar to bandage her elbow. I find that those symptoms had an immediate adverse effect upon Mrs Marks' capacity for work.
[9] Decision [180], [195], [197], [209].
In terms of the onset of symptoms, the Arbitrator made the following findings:
(a)if there were symptoms of neck pain in 2016, they were not so severe as to cause the Appellant to seek treatment from her general practitioner;[10]
[10] Decision [133].
(b)the Appellant did not suffer 'blows' to her head in that she did not ever hit her head forcefully at work - any impacts between her head and the cabinet were not sufficiently forceful to produce disc prolapses;[11]
[11] Decision [217].
(c)the Appellant was required in the course of her duties for the Respondent to lift and carry crates and containers of food, including chicken pieces (though the Arbitrator was not able to make a finding as to the maximum weight she was required to lift);[12]
[12] Decision [108] - [109].
(d)the first date on which the Appellant noticed symptoms of cervical radiculopathy was, at the earliest, 25 August 2017 when she was opening or attempting to open a coke bottle;[13]
[13] Decision [132], [208].
(e)symptoms of pain and bilateral radiculopathy did develop over a period of time from August 2017;[14]
[14] Decision [169].
(f)on the weekend of 9 and 10 September 2017 the Appellant engaged in gardening;[15]
[15] Decision [186].
(g)the Appellant deliberately portrayed her gardening in general as a relatively non-strenuous activity and minimised the extent of her gardening;[16]
(h)the gardening on the weekend of 9 and 10 September included spreading of a large amount of mulch, for several hours;[17]
(i)whilst doing this gardening, the Appellant experienced symptoms of cervical radiculopathy;[18]
(j)the symptoms which the Appellant noticed while she was mulching over the weekend of 9 and 10 September persisted beyond the weekend and caused her pain and disability when she returned to work after the weekend;[19]
(k)it was the symptoms in (i) persisted until she had undergone surgery in June 2018;[20]
(l)the Appellant complained to each of Ms Arunkumar, Ms Jones and Ms Bozanich about symptoms involving her arm which she thought may be related to gardening the previous weekend;[21]
(m)the Appellant sought and was given help by her colleagues in the performance of her duties immediately after the weekend in which she carried out gardening activities that give rise to her symptoms;[22]
(n)on 12 September 2017 whilst at work the Appellant experienced symptoms of cervical radiculopathy whilst closing Ziploc bags containing chickens;[23]
(o)the Appellant did not give any evidence to the effect that lifting of crates of chicken on 12 September 2017 caused any noticeable exacerbation or aggravation of her symptoms suffered on that day;[24] and
(p)the Appellant did not give any evidence that she moved crates of chicken after she became symptomatic, rather her colleagues undertook this task for her.[25]
[16] Decision [177].
[17] Decision [178].
[18] Decision [209].
[19] Decision [187].
[20] Decision [169], [187], [209].
[21] Decision [195].
[22] Decision [199].
[23] Decision [44], [190].
[24] Decision [211].
[25] Decision [227].
The Respondent adduced the clinical notes of two general practitioners who saw the appellant between 11 October 2017 and 12 November 2017, Dr Ugo Egesi and Dr Zachery Nathan.
As to Dr Egesi's clinical notes, the Arbitrator observed:[26]
The Respondent adduced clinical notes of Mrs Marks' usual general practitioner, Dr Ugo Egesi, made on 11 October 2017. These clinical notes recorded Mrs Marks complaining of pain in her right elbow and right wrist with distal tingling and burning. Those notes made no mention of any incident that triggered or had temporally preceded these symptoms nor any incident that Mrs Marks thought may have triggered her symptoms. In the Marks Statement at [32] Mrs Marks stated in relation to this consultation, 'the doctor told me to stop what I was doing, I cannot recall what the case was. He didn't give me any treatment'.
Dr Egesi did not provide any further report, nor did he give evidence at the arbitration hearing.
[26] Decision [70].
As to Dr Nathan, given the issues in the appeal, it is necessary to quote the Arbitrator's summation of his evidence:[27]
[27] Decision [71] - [74].
On 31 October 2017 Mrs Marks attended upon Dr Nathan, who she had met at the delicatessen counter when he was a customer, and with whom, as set out above, she had already spoken about her right upper limb symptoms. Dr Nathan recorded that;
(a)Mrs Marks had suffered right elbow pain and wrist pain for three months;
(b)The pain had commenced after mulching and then worsened during work at Coles; and
(c)Mrs Marks worked at the delicatessen counter and her work involved lifting and repetitive movements.
On that date, Dr Nathan diagnosed carpal tunnel syndrome.
Mrs Marks again consulted Dr Nathan on 3 November 2017 complaining of a worsening elbow, wrist and shoulder pain. Dr Nathan noted that Mrs Marks was experiencing 'entrapment symptoms' with neck flexion to the right. Dr Nathan recorded that Mrs Marks was managing coding at work but not working in the delicatessen or lifting. Dr Nathan arranged for an MRI scan of the cervical spine on the basis of symptoms of radiculopathy in the right arm.
Mrs Marks was reviewed by Dr Nathan on 11 November 2017 when the report of the MRI scan of her cervical spine was available. The MRI scan was reported as revealing:
'Moderate changes of cervical spondylosis, most severe at C5/6 C6/7. There is mild spinal canal stenosis at both levels with effacement at the ventral space. At C5/6, there is a superimposed 4 mm posterolateral protrusion with potential left C5 nerve impingement. Multilevel foraminal stenosis is present, most prominent on the right at C5/6 and C6/7 and on the left at C6/7'.
On 12 November 2017 Dr Nathan provided a First Medical Certificate under the Act which gave a date of injury of 12 September 2017 and referred to the gradual onset of symptoms in the right hand and elbow 'with symptoms now moving to the left side'. The certificate described the symptoms as 'tingling, numbness and pain' in the right wrist and elbow and pain extending into the neck and shoulder. The certificate gave as a diagnosis 'cervical spondylosis and radiculopathy'.
Dr Nathan did not provide any further report, nor did he give evidence at the arbitration hearing.
Ms Jones gave evidence of overhearing a conversation between the Appellant and Dr Nathan at the delicatessen counter, something disputed by the Appellant.[28]
[28] Decision [64].
The Appellant gave evidence of an additional comment made by Dr Nathan in one of these consultations, though the Arbitrator found this evidence to be implausible.[29]
[29] Decision [203].
The Arbitrator then drew a Jones v Dunkel[30] inference against the Appellant inferring that Dr Nathan's evidence would not have assisted her in establishing that gardening was not the cause of the symptoms with which she presented to him.[31]
[30] Jones v Dunkel [1959] HCA 8; (1959) 101 CLR 298.
[31] Decision [204].

The Arbitrator also drew a Jones v Dunkel inference against the Appellant that Dr Egesi's evidence would not have assisted her in establishing that the onset of persistent symptoms was on 12 September 2017 when she was closing Ziploc seals on bags of chicken.[32]
[32] Decision [206].
The Arbitrator had expert opinion evidence from six medical practitioners.
The first opinion considered was that of Dr John Low, an occupational physician. Dr Low saw the Appellant on 19 December 2017. He provided a report dated 1 January 2018 and a supplementary report dated 18 October 2018. Dr Low opined that the Appellant did not suffer from a work-related cervical spine condition or left upper limb radiculopathy. He noted that the findings on the cervical spine MRI are frequently present in asymptomatic individuals and are degenerative in origin. Further, the initial symptoms had presented acutely when the Appellant was at home and, although they were more noticeable with work activities, the Appellant would have suffered the symptoms irrespective of her work given that the original symptoms were present outside of work.[33]
[33] Decision [110] - [119].
The second opinion considered was that of Dr Evan Jenkins, an occupational physician. The history of the onset of symptoms provided by Dr Jenkins differed from the evidence which the Arbitrator otherwise found. So it is necessary to quote from the Decision in detail:[34]
[34] Decision [122] - [128].
The occupational physician Dr Jenkins recorded in his report dated 8 February 2018 a history which involved Mrs Marks developing intermittent mechanical neck pain from late 2016 which commenced while she was working as a delicatessen assistant for the Respondent.
Dr Jenkins records that Mrs Marks first felt neck pain when she was repetitively learning into the delicatessen display cabinets, reaching forward and retrieving cheese and salad containers and large pieces of meat. He records that Mrs Marks would sometimes hit her head as she withdrew from the cabinet after retrieving produce.
Dr Jenkins reports that it was in July 2017 that Mrs Marks said that she first felt a twinge in her right thumb and index finger when she was shifting mulch, and that soon after this she felt a similar twinge of pain when opening a bottle. He reports that Mrs Marks subsequently suffered symptoms in her right upper limb sometime in August 2017 when she was at work cooking and bagging chickens. He recorded that this involved preparing and cooking 30 to 40 chickens before placing them in bags closed with a zip seal which required her to move her prone hand with the wrist flexed and the thumb and forefinger gripping and sliding the zip seal across her body. Dr Jenkins reported that Mrs Marks recalls that this caused a recurrence of the previous twinge in her thumb and index finger which subsequently intensified and worsened. Dr Jenkins reports that it was around this time that Mrs Marks also developed significant pain in the medial aspect of the elbow, marked fatigue and aching pain in the radial aspect of the right forearm.
References in Dr Jenkins' report symptoms relating to the cervical spine in 2016
Dr Jenkins' report contains multiple references to intermittent symptoms of mechanical neck pain arising in 2016.
At the commencement of the arbitration, Mrs Marks submitted that amendments should be made to Dr Jenkins' report to correct what she contended were a series of typographical errors. The Respondent objected to those corrections being made. Even if the Respondent had not objected, I would to have agreed to proceed on the basis that all of the references to 2016 were mere typographical errors. It is not unusual for there to be obvious typographical errors in experts' reports and they are easily dealt with as such. Dr Jenkins' repeated references to 2016 were obviously not typographical errors.
The alternatives to the references to 2016 being typographical errors are that:
(a)Mrs Marks gave an accurate history to Dr Jenkins and that it was accurately recorded that symptoms commenced in 2016;
(b)Mrs Marks was mistaken when she gave a history to Dr Jenkins; or that
(c)Dr Jenkins mistakenly recorded mechanical neck pain occurring in 2016.
As noted above, the discrepancies between Mrs Marks' evidence and Dr Jenkins' evidence as to the times when particular symptoms were suffered are not confined to Dr Jenkins' reference to symptoms arising in 2016. Dr Jenkins twice refers to Mrs Marks experiencing an initial 'twinge' in her right thumb and index finger after shifting mulch in July 2017 when it was Mrs Marks' evidence that this occurred on 9 September 2017. Further, Dr Jenkins stated in the second paragraph of his report:
'After two episodes at home she was asymptomatic for some weeks before she first experienced this at work while sealing chicken bags. Her neck, right arm and neck symptoms deteriorated and from September to October 2017 she developed increasing left arm pain in addition.'
Mrs Marks' evidence is that she does not say that 'some weeks' passed between the mulching episode and the provocation of symptoms while sealing chicken bags. This inconsistency in respect of timing 'is' of some significance to the question as to whether there was any time between Mrs Marks' mulching and her relevant sealing of the chicken bags when she was asymptomatic in respect of her cervical radiculopathy.
The Arbitrator then records that, at the conclusion of the Arbitration, the Appellant made an application to introduce a further report of Dr Jenkins. The Arbitrator declined this application, for reasons which are not the subject of challenge in this appeal.[35]
[35] Decision [129] - [135].
In her final analysis, the Arbitrator discounted the opinion of Dr Jenkins due to the divergence between the facts he relied on at the facts as found:[36]
The relevant history recorded by Dr Jenkins is also significantly at odds with my findings of fact referred to above. In particular, I do not accept that Ms Marks suffered from a mere temporary twinge of pain in the thumb and right index finger when she was shifting mulch, as Dr Jenkins has recorded and assumed, but rather that she suffered marked and lasting symptoms of cervical radiculopathy, the severity of which compromised her capacity for work immediately upon her return to work after the weekend on which the gardening occurred. Further, to the extent that Dr Jenkins places reliance on the process of cooking the chickens as opposed to putting them in bags and sealing the bags, his history is at odds with Mrs Marks' evidence given during the hearing that it was specifically the sealing of the bags that caused in the alleged onset of her symptoms.
The facts on which Dr Jenkins has based his opinion to the effect that Mrs Marks suffered an exacerbation of her pre-existing condition by reason of carrying chicken crates and sealing chicken bags on 12 September 2017 have not been established. … The variance between the facts as found and the facts assumed by Dr Jenkins extends to critical or central factual assumptions on which Dr Jenkins' opinion is based, such that there is no evidentiary foundation for his opinion, and such that I cannot rely upon it as evidence of causation for the purposes of paragraph (a) of s 5(1) of the Act: Makita [85].
[36] Decision [215] - [216]. The reference to Makita is a reference to Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705, 743 ‑ 744 (Heydon JA).
The third opinion considered was that of Mr Michael Kern, the Appellant's treating neurosurgeon. Given the centrality of his evidence to the Appellant's appeal, it is necessary to quote in detail:[37]
The only report of Mr Kern that was put into evidence was that dated 29 June 2018. I note from the submissions filed on behalf of Mrs Marks that an earlier report of Mr Kern exists. It appears to me from those submissions that the earlier report has been provided to the Respondent.
Mr Kern reported that Mrs Marks gave a history of working for 6 months in the Respondent's produce department, a period of working in night fill and then 2 years in the delicatessen department.
Mr Kern did not record whether Mrs Marks' work was full-time or part -time or specify Mrs Marks' hours of work.
Mr Kern was asked whether Mrs Marks' condition was a direct result of her work for the Respondent and whether work was a significant contributing factor to her symptoms. Mr Kern was also asked whether Mrs Marks had suffered a recurrence, aggravation or acceleration of any pre-existing condition if so, whether the employment was a contributing factor to a significant degree. Mr Kern did not in his report clearly delineate how each of those discrete questions was answered.
[37] Decision [136] - [139].
The Arbitrator then quoted the following passage from Mr Kern's report:[38]
Mrs Marks started to work for Coles in September 2014. Prior to this she was a housewife and cared for her mother. She reports that the work at Coles was physically quite demanding and a significant change compared to the duties around the house which she did feel were physical. This includes gardening which she has done maintained about 50 roses. The first 6 months of her employment with Coles involved lifting crates in the produce department and filling vegetables and fruit onto shelves. This involved frequent lifting and bending. She subsequently transferred within Coles to do night‑filling. After this she changed to the deli department where she has been for more than 2 years. Her work at the deli department requires frequent lifting or chicken crates, repetitive opening and closure of chicken bags, accessing cabinets at low levels requiring bending and turning her neck. Considering the duties that she performed for 3 years prior to her onset of symptoms suggest that the employment was a significant contributing factor to her symptoms. Her symptoms are caused by C5/6 and C6/7 spondylosis with disc protrusions at these levels. I consider her work duties as the most likely cause for her cervical pathology. Other cervical spine levels demonstrate age‑appropriate degeneration whereas the C5/6 and C6/7 levels demonstrate disc prolapse. Degeneration alone is therefore unlikely to have caused the pathology at the C5/6 and C6/7 levels as one might reasonably expect similar degenerative findings at other levels. It is much more likely that the strenuous activities at work have been a major contributing factor.
…
Mrs Marks' symptoms first manifested themselves when she opened a bottle on 25 August 2017. At the time she was at home. She felt discomfort in her and index finger of the right hand. The second time she felt discomfort in thumb and index finger on the 9^th September 2017 when she was on all fours moving pieces of mulch away from the roses in her garden. She described the feeling as a cramp in her thumb and index finger and she immediately stopped this activity. The most likely mechanism was that she had developed disc bulges at C5/6 and C6/7 that at the time were comparatively mild and only caused nerve compression symptoms with arm and finger discomfort when she moved her neck into a certain position, like the extended position while she was kneeling in the garden. The opening of the bottle was likely an incidental activity unrelated to her cervical pathology. She became much more severely symptomatic on 12 September 2018 when she was at work opening and closing chicken bags and lifting crates of chicken. She felt weakness in her hand and dropped the chicken bag and developed bilateral upper limb discomfort involving arms and hands in bilateral C6 and C7 dermatomes. She subsequently went off work on 6 November 2017 due to her severe discomfort. Almost certainly the disc prolapses at C5/6 and C6/7 had worsened on 12 September 2018 when she was performing heavy physical activities lifting crates of chicken at work. The symptoms of bilateral arm symptoms, headaches and neck pains are entirely consistent with the C5/6 and C6/7 disc protrusions and spondylosis.
The most likely cause of the C5/6 and C6/7 dis degeneration with disc bulging and neural compromise at these level are work-related activities. Considering Mrs Marks' considerable physical demands of repetitive lifting and repetitive activities opening and closing chicken bags and lifting crates and heavy objects over the 3 years leading up to injury I am of the opinion that this is the most likely cause of her cervical injury. The significant deterioration and worsening of the injury occurred at work and this would have been associated with further disc protrusion causing more severe nerve compression. I think that it is very unlikely that the injury was initially caused at home but this cannot be entirely excluded. It would have however been a very mild cervical injury without significant nerve compression.
[38] AAB 144 - 145.
Again, in her final analysis, the Arbitrator declined to place weight on the opinion of Mr Kern:[39]
Mr Kern based his opinion on a history which included Mrs Marks becoming 'much more severely symptomatic on 12 September 2018 (sic, 2017) when she was at work opening and closing chicken bags and lifting crates of chicken'. The evidence did not establish that Mrs Marks became much more severely symptomatic when closing the Ziploc seals on bags containing chickens at any time, including on 12 September 2017. I find that her symptoms experienced at that time were a continuation of the symptoms from which she suffered when she came to work after her weekend gardening. Further, Mr Marks did not give any evidence to the effect that lifting crates of chicken on 12 September 2017 caused any noticeable exacerbation or aggravation of her symptoms suffered on that day. To the contrary, even when she was taken through the entire process of cooking chickens during re‑examination, she restated that it was only when she was closing the seals on the chicken bags that she experienced a noticeable exacerbation of her symptoms.
Mr Kern reports that on 12 September 2018 Mrs Marks felt weakness in her hand and dropped a 'chicken bag'. This account conflates Mrs Marks' evidence as to her experience of pain on 12 September 2017 and her evidence that she later suffered weakness that caused her to drop a chicken bag at a later date and that she later suffered pain in her left arm in addition to suffering pain in her right arm. Mr Kern has also described a sudden, severe experience of symptoms on 12 September 2017 which did not in fact occur.
The matters in respect of which my findings of fact differ from the facts relied upon by Mr Kern are matters that are critical to Mr Kern's opinion as to the cause of Mrs Marks' symptoms on 12 September 2017 in that they go to the key aspects of the clinical history upon which his opinion is based – the nature and severity of Mrs Marks' symptoms prior to the relevant activities at work, the nature of the activities at work that Mr Kern assumed provoked symptoms and the nature and severity of the symptoms and disability that immediately followed performance of those assumed activities.
Mr Kern's opinion that closing the Ziploc seals on the chicken bags and/or lifting crates of chicken on 12 September 2017 were causative or contributory to the existence or severity for Mrs Marks' condition is based on facts for which there is no evidentiary foundation. I cannot rely on Mr Kern's opinion in that regard as providing evidence of an injury caused by an accident in the course of Mrs Marks' employment for the purpose of par (a) of s 5(1) of the Act: Makita [85].
[39] Decision [211] - [214].
The fourth opinion considered was that of Mr Ian Skinner, an orthopaedic surgeon. As to his opinion the Arbitrator stated:[40]
Mr Skinner stated in his report that Mrs Marks 'reported that she suffered a number of blows to the heard in the course of her duties' and stated that on 'many' occasions 'the knock removed not only her hat but also her hairnet'. Mr Skinner opines that it was these 'recurrent blows to her head' that were the cause of changes in her cervical spine. Mr Skinner's use of the word blows' indicates that he understood these knocks on the head to be forceful.
[40] Decision [147].
In her final analysis, the Arbitrator also declined to place weight on his opinion:[41]
As to Mr Skinner, as noted above he attributed the pathology in respect of Mrs Marks' cervical spine to what he described as recurrent blows to Mrs Marks' head. I find that Mrs Marks did not suffer 'blows' to her head in that she did not ever hit her head forcefully at work. I find that the impacts between her head and the cabinet were not sufficiently forceful to produce disc prolapses. There is no evidentiary foundation for Mr Skinner's opinion and I place no reliance upon it as evidence of causation for the purposes of par (a) of s 5(1) of the Act: Makita [85].
[41] Decision [217].
The fifth opinion considered was that of Professor George Sikorski, an orthopaedic surgeon. Professor Sikorski opined that, while the Appellant's condition was consistent with disc prolapse at C5/C6, there was no reason to suspect that this was in any way related to her work. Rather, the cervical disc prolapse was degenerative in origin. He was asked whether, in light of the Appellant's vocational history, it was possible to state on the balance of probabilities that her work with the Respondent was a significant contributing factor to the disc protrusions and prolapses. He opined that her previous employment, specifically her work as a security guard and as a sports recreation officer, would have been much more likely to cause injuries to the neck than working on the delicatessen counter at Coles.[42]
[42] Decision [151] - [154].
The final opinion considered was that of Mr George Wong, a neurosurgeon. Mr Wong said he could not find any particular injury which caused the onset of the symptoms. He opined that the likely onset of the Appellant's symptoms was really related to degeneration. He was not 'particularly convinced' that the symptoms were related to any particular injury at work. Rather, on the balance of probabilities, thought that the symptoms related to underlying degenerative changes rather than any particular injury.[43]
[43] Decision [155] - [160].
In relation to Dr Low, Professor Sikorski and Mr Wong, the Arbitrator concluded that each took into account the Appellant's history as to the onset of symptoms which was inconsistent with her findings. It is not entirely clear what this inconsistency is. It appears to be the finding that the Appellant 'experienced the onset of cervical radiculopathy when she was gardening at home on 9 September 2017 and that her symptoms continued when she was at work after that date'.[44] Though, as the Appellant asserts in the Appeal, there is an inconsistent finding that the Appellant experienced symptoms of cervical radiculopathy on 25 August 2017 when she was attempting to open a bottle.[45]
[44] Decision [219].
[45] Decision [208].
The Arbitrator went on to observe that: [46]
even with that history, none of those practitioners accepted that the sealing of chicken bags on 12 September 2017 was the cause of the symptomatic disc prolapses, and their opinions provide no support for a finding pursuant to par (a) of s 5(1) of the Act.
[46] Decision, [218].
Consequently, the Arbitrator concluded:[47]
I find that there was no accident arising out of or in the course of Mrs Marks' employment which caused any injury for the purposes of paragraph (a) of the definition of that term in s 5(1) of the Act. Rather, Mrs Marks experienced the onset of cervical radiculopathy when she was gardening at home on 9 September 2017 and her symptoms continued when she was at work after that date.
[47] Decision [219].
The Arbitrator then considered whether there was an injury for the purposes of paragraph (d) of the definition of injury in WCIMA s 5(1). This paragraph required the appellant to show that 'the recurrence, aggravation, or acceleration of any pre-existing disease where the employment was a contributing factor to that recurrence, aggravation, or acceleration and contributed to a significant degree'.

The Arbitrator determined that there was no recurrence of a disease in the sense of a return or renewal of, or reversion to, the previous state.[48] This was because the Appellant continued to suffer symptoms of cervical radiculopathy after gardening on the weekend prior to the alleged recurrence when sealing chicken bags.
[48] Decision [221] - [222], citing the decision in FAI General Insurance Co Ltd v Goulding [2004] WASCA 167 [68] (Templeman J) (FAI).
The Arbitrator first dealt with the issue of whether there was 'post‑symptomisation aggravation or acceleration', concluding:[49]
[49] Decision, [223] - [235], with the quote at [235].
For the following reasons I am not satisfied to the required standard that Mrs Marks' work for the Respondent after she became symptomatic contributed, to a significant degree, to any acceleration or aggravation of her pre-exiting condition;
(a)Mrs Marks worked for a period of about six weeks, on a part‑time basis after 12 September 2017;
(b)Mrs Marks did not give evidence that, during that period, she suffered any particular insult to her cervical spine whilst at work;
(c)Mrs Marks agreed that during that period her colleagues assisted her with the heavier tasks required in her position, including the cooking of chickens, the sealing of chicken bags, lifting and carrying food and cleaning;
(d)Mrs Marks was allocated to lighter duties for some of her hours of work during this period;
(e)The tasks that Mrs Marks identifies as provoking cervical radiculopathy during that period are not heavy tasks that are likely to worsen the underlying condition;
(f)Whilst Mrs Marks' symptoms progressed during the period, they continued to progress after the period, suggesting that following symptomisation caused by gardening, there was inevitable persistence or progression of symptoms irrespective of the nature of Mrs Marks' activities; and
(g)There is no medical evidence that specifically addresses the likelihood that such tasks as Mrs Marks did carry out post‑symptomisation would worsen the disc protrusions or prolapses to a significant degree.
The Arbitrator then dealt with the issue of whether there was 'pre‑symptomisation aggravation or acceleration', concluding:[50]
I am not persuaded that, on the balance of probabilities, the tasks required of Mrs Marks in any, or all, or any combination of her roles with the Respondent over the period of her employment with it have made a contribution, to a significant degree, to any acceleration or aggravation of Mrs Marks' pre-existing degenerative disease in her cervical spine.
[50] Decision [264].
In each case, the Arbitrator applied the factors set out in WCIMA s 5(5).
Consequently, the Arbitrator concluded that she was not persuaded that the Appellant had suffered an injury for the purposes of the definition in par (a) or (d) of the definition in WCIMA s 5(1). The burden being on the Appellant to do so, the Arbitrator dismissed the Application.

The District Court Appeal

By appeal notice filed 11 July 2020, the Appellant appealed from the Decision. The appeal notice was filed within 28 days after the day on which the written reasons for the Decision were given to the Appellant as required by WCIMA s 247(4).
On 18 July 2019 the Respondent filed a Notice of Respondent's Intention in which it advised that it intended to take part in the appeal and would argue that the Decision be upheld on the grounds relied on by the Arbitrator.
On 22 January 2020 the Appellant filed submissions in support of the appeal. These submissions were replaced by amended submissions file on 10 February (Appellant's Submissions). She also filed an appeal book.
On 22 January 2020 the Respondent filed submissions in position to the appeal (Respondent's Submissions). The Respondent also filed an appeal book.[51]
[51] I will refer to documents in the Respondent's appeal book by the reference 'RAB #'.
On 11 February 2020, the Appellant filed an Amended Appeal Notice. As the hearing on 17 February 2020, I gave the Appellant leave to rely on the Amended Appeal Notice.
If, as is the case here, written reasons for an Arbitrator's decision under WICMA pt XI in respect of a dispute are given to a party to the dispute, a party may, with the leave of the District Court, appeal to the District Court against the decision.[52] The bases on which leave may be granted are set out in WCIMA s 247(2):
[52] WCIMA s 247(1).
(2)…, the District Court is not to grant leave to appeal unless -
(a)in the case of an appeal in which an amount of compensation is at issue -
(i)a question of law is involved and the amount at issue in the appeal is both -
(I)at least $5 000 or such other amount as may be prescribed by the regulations; and
(II)at least 20% of the amount awarded in the decision appealed against;
or
(ii)a question of law is involved and, in the opinion of the District Court, the matter is of such importance that, in the public interest, an appeal should lie;
and
(b)in any other case, a question of law is involved.
The Appellant relies on both WCIMA s 247(2)(a)(i) and s 247(2)(b). However, as the Appeal is one in which an amount of compensation is in issue, it falls within s 247(2)(a) and not s 247(2)(b). The effect of the Decision was to deny the Appellant weekly compensation for a period in excess of 2 years. The Respondent did not assert that the amount in issue was not in excess of $5,000, with the Decision being to the effect that no amount is payable (satisfying WCIMA s 247(2)(a)(i)(I) and s 247(2)(a)(i)(II)).
The remaining issue is whether the Appeal involves a question of law. A decision will not 'involve' an error of law 'unless the error is material to the decision in the sense that it contributes to it so that, but for the error, the decision would have been, or might have been, different'.[53]
[53] Australian Broadcasting Tribunal v Bond [1990] HCA 33; (1990) 170 CLR 321, 353 (Mason CJ) (Bond); BHP Billiton Iron Ore Pty Ltd v Brady [2008] WASCA 250 [15] (Pullin JA, with whom Buss & Wheeler JJA agreed) (Brady).
If there is a question of law involved, leave should be granted if, in all the circumstances of the particular case, it is in the interests of justice that there be a grant of leave.[54]
[54] Waite v Alcoa of Australia Ltd [2020] WASCA 1 [78] (judgment of the court) (Waite (CA)); Engine Protection Equipment Pty Ltd v Miller [2018] WASCA 55 [46] (judgment of the court); Brady [20]; Paridis v Settlement Agents Supervisory Board [2007] WASCA 97 [16] (Buss JA, with whom Wheeler & Pullin JJA agreed).
The parties were content to have the issue of whether the Appellant should be granted leave to appeal determined with the substantive hearing. Where this occurs, the appropriate approach is to deal with the question of leave after considering the merits of the proposed grounds of appeal. The court will then be in a position to either grant leave and uphold or dismiss the appeal, or refuse leave to appeal.[55] In the main, I will adopt this course. However, for some points, for ease of analysis, I have dealt with the issue of leave with the issue of whether the ground asserts a question of law.
[55] Brady [14].
Except as provided by WCIMA pt XIII or WCIMA s 267, the appeal is to be conducted in accordance with the rules of court of the District Court.[56] As no leave has been granted otherwise, the appeal is to be conducted on the basis of the evidence before the Arbitrator.[57]
[56] WCIMA s 247(5).
[57] WCIMA s 247(6).
The appeal is to be by way of review of the decision appealed against.[58] Unless the 'review' persuades the court that the Arbitrator's decision should be varied, discharged or otherwise disturbed, it should stand.[59]
[58] WCIMA s 247(5).
[59] Pacific Industrial Co v Jakovljevic [2008] WASCA 60 [20] - [26] (Wheeler JA, with whom Buss & Pullin JJA agreed).

Issues arising for determination

The grounds of appeal in the Amended Appeal Notice are detailed. They give rise to 14 issues for determination.
•Did the Arbitrator err in fact and law in approaching and determining the statutory question of 'significant contribution' for the purposes of determining a WCIMA s 5(d) injury (ground 4.5)?
•Did the Arbitrator err in relation to the finding that the Respondent's witnesses collaborated or colluded on a central factual issue (ground 1.1)?
•Did the Arbitrator err in law in the application of the principle in Jones v Dunkel in relation to the evidence of Dr Nathan and Dr Egesi (grounds 2.1, 2.3 and 2.4)?
•Did the Arbitrator deny the Appellant procedural fairness in relation to the Jones v Dunkel findings (ground 2.2)?
•Did the Arbitrator err in law in finding that the Appellant experienced symptoms of cervical radiculopathy on 25 August 2017 when she was attempting to open a bottle (grounds 4.2 and 5.2(b))?
•Did the Arbitrator err in law making a finding that the onset of cervical radiculopathy began when the Appellant was gardening at home on 9 September 2017 (ground 4.1)?
•Did the Arbitrator err in law in making the finding that the Appellant's gardening may have been casually related to her disc protrusion (ground 4.3)?
•Did the Arbitrator err in law in finding that the Appellant had engaged in other activities that over time that may have contributed to cervical spondylosis and/or disc protrusions or prolapses (ground 4.4)?
•Did the Arbitrator err in discounting the opinion evidence of the Mr Kern and Dr Jenkins (grounds 5.1 and 5.2(c))?
•Did the Arbitrator err in law in making a finding that the request to Ms Arunkumar bandage the elbow was made in September 2017 (ground 5.2(a))?
•If the grounds of appeal disclose errors of law, should leave to appeal be granted?
•If leave is granted, does a review disclose an error in the Decision?
•Did the Arbitrator demonstrate a reasonable apprehension of bias against the Appellant (grounds 1.2 and 3)?
•What final orders are appropriate?
Counsel for the Appellant invited the court to only consider the issue of perceived bias in the event that the appeal was otherwise unsuccessful.

Did the Arbitrator properly apply WCIMA s 5(d)?

Ground of appeal 4.5 is in the following terms:
Further, or in the alternative, the learned Arbitrator erred in fact and law in approaching/ determining the statutory question of 'significant contribution' for the purpose of determining a s5(d) injury.
As I have observed, the Appellant relied on the definition of injury in pars (a) and (d) of the definition in WCIMA s 5(1). Paragraph (d) provides:
injury means … (d) the recurrence, aggravation, or acceleration of any pre-existing disease where the employment was a contributing factor to that recurrence, aggravation, or acceleration and contributed to a significant degree; …
The Appellant did not take issue with the Arbitrator's finding that there had been no recurrence of a pre-existing disease.
The Appellant's position, as I understand it from submissions, is that the Arbitrator misapplied the par (d) definition by artificially dividing the analysis into the Appellant's activities at work before and after 12 September 2017, but never considering the issue of whether the Appellant's activities on 12 September 2017 contributed, to a significant degree, to any recurrence, aggravation or acceleration of any pre‑existing disease. Rather, the correct question was, in the words of Templeman J in FAI, whether, on 12 September 2017, 'there was a recurrence, aggravation or acceleration of a pre‑existing [disease] to which the respondent's employment had been a contributing factor and had contributed to a significant degree'.[60]
[60] FAI [72].
In my view, that the Arbitrator did not expressly consider the issue of whether the Appellant's activities on 12 September 2017 contributed, to a significant degree, to any recurrence, aggravation or acceleration of any pre-existing disease. This is evident from the following passages which framed the Arbitrator's reasoning on this point:[61]
Was there an injury for the purposes of paragraph (d) of s 5(1) of the Act?
It is necessary for me to determine whether the evidence establishes that Mrs Marks' activities at work both before and after 12 September 2017 contributed, to a significant degree, to any recurrence, aggravation, or acceleration of any pre-existing disease. These periods of time must be considered separately because Mrs Marks' work tasks differed in the respective periods prior and subsequent to her symptoms.
…
Was there post-symptomisation aggravation or acceleration for the purpose of paragraph (d) of s 5(1) of the Act?
It is necessary for me to determine whether there was an injury for the purposes of paragraph (d) of s 5(1) of the Act within the period from the date on which Mrs Marks' relevant symptoms were first experienced until Mrs Marks' work with the Respondent ceased.
…
Was there pre-symptomisation aggravation or acceleration for the purpose of paragraph (d) of s 5(1) of the Act?
It is also necessary for me to determine whether, on the balance of probabilities, Mrs Marks' work for the Respondent contributed to a significant degree to any acceleration or aggravation of her degenerative spinal disease before she became symptomatic, and again, I must take into account the factors referred to in s 5(5).
[61] Decision [220], [223], [236].
Counsel for the Respondent submitted that the Arbitrator implicitly determined that the Appellant's activities on 12 September 2017 did not contribute, to a significant degree, to any recurrence, aggravation or acceleration of any pre-existing disease in the finding that there was no injury within WIMCA s 5(1)(a). That paragraph required the Appellant to establish that she sustained 'a personal injury by accident arising out of or in the course of the employment, or whilst [she] is acting under the employer's instructions'.[62]
[62] WCIMA s 5(1).
However, the two inquiries are different. As to par (a), the expression 'personal injury by accident' is a compound expression. The term 'injury' denotes that there must be some definite or distinct physiological change or physiological disturbance for the worse, which, if not sudden, is at least identifiable. The use of the term 'accident' denotes the unexpected nature of the events which constitutes the injury.[63] The personal injury by accident must then arise 'out of or in the course of the employment, or whilst the worker is acting under the employer's instructions'.
[63] Military Rehabilitation and Compensation Commission v May [2016] HCA 19; (2016) 257 CLR 468 [45] - [48] (French CJ, Kiefel, Nettle & Gordon JJ) (May); Jones v Ramsay Health Care Pty Ltd [2019] WADC 97 [28] - [45] (Gething DCJ) (Ramsay Health Care); Waite (CA) [47], [61], [80]; Waite v Alcoa of Australia Ltd [2018] WADC 147 [143] - [146] (Troy DCJ) (Waite (DC)).
As to par (d), the Appellant did not take issue with the Arbitrator's recitation of the law that an 'aggravation' required 'that the relevant activity was likely to have increased the severity of the pre-existing spinal stenosis or the pre-existing disc bulges, that is, that the disease has been made worse rather than simply becoming worse'.[64] The employment need only be a contributing factor to that aggravation, albeit that the contribution must be 'to a significant degree'.
[64] Decision [232] (emphasis in original), citing FAI [68] and Ogden Industries Pty Ltd v Lucas [1967] HCA 30; (1967) 116 CLR 537, 553 (Barwick CJ, Kitto, Taylor, Windeyer & Owen JJ) (Ogden).
It is evident from these definitions that an activity at work may be an aggravation of a pre-existing injury, without necessarily being a personal injury by accident. So I do not accept the Respondent's argument that the Arbitrator's findings on par (a) constitute an implicit determination that the Appellant's activities on 12 September 2017 did not contribute, to a significant degree, to any recurrence, aggravation or acceleration of any pre-existing disease for the purposes of par (d).
For these reasons it is apparent to me that the Arbitrator did not turn her mind to the question of whether the appellant's activities on 12 September 2017 contributed, to a significant degree, to any aggravation or acceleration of any pre-existing disease for the purposes of par (d). In doing so, in my view, the Arbitrator misunderstood the nature of the statutory inquiry. This is an error of law.[65]
[65] Suleski v Pilbara Iron Company (Services) Pty Ltd [2018] WASCA 147 [19] (reasons of the court); Jenkins v Western Australian Department of Training [1999] WASCA 199 [31] - [41] (Anderson J, with whom Malcolm CJ & Ipp J agreed).
I deal with the issue of leave below.

Did the Arbitrator err in relation to the findings that the Respondent's witnesses collaborated or colluded?

The second issue is set out in detail in ground 1.1:
Having found (at [164]) that the respondent's witnesses collaborated or colluded or confabulated on a central factual issue, the learned Arbitrator erred in law in limiting the significance/relevance of that finding merely to the question whether those witnesses' other evidence was generally truthful. Had the learned Arbitrator not committed that error, she would not or could not reasonably have concluded that the worker 'deliberately' minimised the extent of her gardening activities (at [177] - [178], [190]).
It is instructive to quote in full the Arbitrator's findings as to the credibility of the Respondent's witnesses:[66]
It was my impression of Ms Arunkumar, Ms Jones, and Ms Bozanich that they each gave an honest account of their own recollections both when making their statements and when giving their oral evidence. All were unshaken in cross examination.
All three of these witnesses were cross examined about the manner in which their statements were produced and whether there had been any discussion between them before and/or after they gave their statements. Save for the admission of Ms Bozanich referred to below, this cross examination did not elicit any admissions of collusion.
Ms Bozanich admitted that she discussed the timing of the onset of Mrs Marks' symptoms with Nicole Ladd. It is possible that Ms Arunkumar and Ms Jones also engaged in a discussion about this with others and collectively arrived at the position that the relevant events occurred in October. None of the witnesses had any means of being sure of the timing of their respective relevant conversations with Mrs Marks so it is understandable that they may have discussed that question with others, or with one another, without appreciating that there was anything untoward about them doing so. I do not consider that any such discussion taints the remainder of their evidence.
As I have already observed, Ms Ladd was not available for the trial, and the Arbitrator placed no reliance on her statement.[67]
[66] Decision [162] - [164].
[67] Decision [166].
Having quoted these passages, it is readily apparent that this ground must fail. There was no finding that the Respondent's witnesses collaborated, colluded or confabulated their evidence. In fact, the Arbitrator preferred the evidence of the Appellant as to the timing of the emergence of symptoms.[68] In any event, the stated error is one of fact alone, being in substance an assertion that the Arbitrator put too much weight on the evidence of the Respondent's witnesses. This was a matter for the Arbitrator in the context of all of the evidence.[69] Indeed, even if what is asserted is that the fact found by the Arbitrator was found wrongly or on a doubtful basis, or was against the weight of the evidence, this does not constitute a question of law.[70] An error of law will only arise if there have been findings of fact made, or inferences drawn, without any evidence to support them.[71] This is not what is asserted in ground 1.
[68] Decision [186].
[69] BHP Billiton Iron Ore Pty Ltd v Treby [2018] WASCA 60 [60] (judgment of the court) (Treby); Erceg v Galati Nominees Pty Ltd [2016] WASCA 112 (Erceg) [32] (judgment of the court); Brady [5].
[70] Treby [41] - [42], [54]; Atanasoka v Inghams Enterprises Pty Ltd [2004] WASCA 17 [21] (Buss JA with whom Wheeler & Pullin JJA agreed); Erceg [31]; Brady [5].
[71] Erceg [31].

As ground of appeal 1 does not involve a question of law, I decline to grant leave in respect of it.

Did the Arbitrator incorrectly apply the rule in Jones v Dunkel?

The third issue is set out in detail in grounds 2.1, 2.3 and 2.4:
2.1The learned Arbitrator erred in law in drawing adverse Jones v Dunkel [1959] HCA 8 inferences against the worker (at [204] and [206]), having failed to take into account:
a)Rule 58 of the Workers' Compensation and Injury Management Arbitration Rules 2011, which prevented the worker from calling any medical practitioner to give oral evidence in the absence of 'exceptional circumstances' being proven and prior leave previously obtained;
b)Rule 59 of the Workers' Compensation and Injury Management Arbitration Rules 2011, which prevents a party from relying upon the evidence of more than 1 medical practitioner in any particular area of practice, without prior leave being obtained;
in circumstances where the said failure to call viva voce evidence from her doctors was not raised by the respondent and this issue appeared for the first time in the learned Arbitrator's reasons for decision.
...
2.3Further or alternatively, having found at [206] that the failure to call Dr Egesi properly gave rise to an adverse Jones v Dunkel inference, the learned Arbitrator erred in law in failing to draw the inference against the respondent, because, as noted at [70], Dr Egesi was the respondent's witness or at any rate, it was not shown or argued that Dr Egesi was in the worker's 'camp'.
2.4Further or alternatively, the learned Arbitrator erred in law (at [204]) in finding that the failure to call Dr Nathan gave rise to an adverse Jones v Dunkel inference, when both parties had adduced evidence from Dr Nathan, there was no basis to conclude that Dr Nathan was in the worker's 'camp', and this issue was never raised by any party at tor after the hearing.
The effect of Workers' Compensation and Injury Management Arbitration Rules 2011 (WA) (WCIMAR) r 58 and r 59 is accurately summarised in these grounds of appeal.
The principles in Jones v Dunkel are set out in the decision of Menzies J, in the context of an appeal against the summing up to a jury in an action for negligence:[72]
In my opinion a proper direction in the circumstances should have made three things clear: (i) that the absence of the defendant… as a witness cannot be used to make up any deficiency of evidence; (ii) that evidence which might have been contradicted by the defendant can be accepted the more readily if the defendant fails to give evidence; (iii) that where an inference is open from facts proved by direct evidence and the question is whether it should be drawn, the circumstance that the defendant disputing it might have proved the contrary had he chosen to give evidence is properly to be taken into account as a circumstance in favour of drawing the inference.
[72] Jones v Dunkel (312) (Menzies J).
Or as more recently outlined by Heydon, Crennan and Bell JJ in Kuhl v Zurich Financial Services:[73]
The rule in Jones v Dunkelis that the unexplained failure by a party to call a witness may in appropriate circumstances support an inference that the uncalled evidence would not have assisted the party's case. That is particularly so where it is the party which is the uncalled witness … The failure to call a witness may also permit the court to draw, with greater confidence, any inference unfavourable to the party that failed to call the witness, if that uncalled witness appears to be in a position to cast light on whether the inference should be drawn …
…
The rule in Jones v Dunkel permits an inference, not that evidence not called by a party would have been adverse to the party, but that it would not have assisted the party …
[73] Kuhl v Zurich Financial Services Ltd [2011] HCA 11; (2011) 243 CLR 361 [63] – [64] (Heydon, Crennan & Bell JJ) (footnotes omitted) (Kuhl). See also: Knell v QZV Pty Ltd [2020] WASCA 23 [7] ‑ [9] (Quinlan CJ) [96] ‑ [97] (Pritchard and Vaughan JJA); Commissioner of the Australian Federal Police v Courtenay Investments Ltd [2016] WASCA 194 [128] - [130] (Martin CJ, with whom Newnes & Mazza JJA agreed).
Their Honours go on to make it clear that the failure to call a witness does not support a stronger inference that the party suppressed evidence that would have been damaging to that party.[74]
[74] Kuhl [64].
As the rule in Jones v Dunkel is part of the rules of evidence, the Arbitrator was not bound to apply it.[75] However, having chosen to apply the rule, it is necessary to determine whether, in doing so, the Arbitrator made either an error of law or a mixed error of fact and law.
[75] WCIMA s 188(2)(a); Cape Australia Holdings Pty Ltd v Burridge [2019] WADC 105 [41] - [44] (Gething DCJ) (Cape Australia).
As the majority in Kuhl make clear, the principles in Jones v Dunkel are rules of inferential reasoning.[76] They define when a failure by a witness to give evidence can logically be used to support the drawing of an inference. In relation to the drawing of inferences, an error of law will not arise unless there is no evidence to support it.[77]
[76] See generally the discussion in Kuhl [63] - [64].
[77] Erceg [31]; Brady [5].
As both a matter of logic and practice, the principles cannot be applied unless certain conditions are met.[78] One condition is that the principles 'in Jones v Dunkel will have no application if the failure to call a witness is explained, for example, by the absence of a witness, coupled with a reasonable explanation for not compelling attendance by subpoena, or where the failure to appear is explained by illness, or other unavailability, or by loss of memory'.[79] In my view, the limits imposed by WCIMAR r 58 and r 59 on the expert medical evidence which may be led at an Arbitration inherently provide a reasonable explanation for not calling a medical witness in a WCIMA arbitration hearing.
[78] Eccles v Koolan Iron Ore Pty Ltd (No 3) [2013] WASC 418 [39] - [47] (Le Miere J) (Eccles).
[79] Hewett v Medical Board of Western Australia [2004] WASCA 170 [205] (Miller J).
There is an additional reason of policy which supports the conclusion in the preceding paragraph. Disputes between parties involved in workers' compensation matters are to be determined 'in a manner that is fair, just, economical, informal and quick'.[80] An arbitrator is to 'act according to equity, good conscience and the substantial merits of the case without regard to technicalities and legal forms'.[81] These principles are reflected in the limits imposed by WCIMAR r 58 and r 59. It would be contrary to these principles if parties felt that they had to routinely seek to call evidence at an Arbitration from additional professional witnesses just to avoid the possibility of a Jones v Dunkel inference being drawn. As a matter of policy, it follows that in a WorkCover arbitration, it is only in the clearest of cases in which an arbitrator would be justified in drawing a Jones v Dunkel inference. This is not such a case.
[80] WCIMA s 3(d).
[81] WCIMA s 188(2)(b).
There is a second reason why there was no basis to draw a Jones v Dunkel inference in relation to Dr Egesi or Dr Nathan. A second pre‑condition is that the principles 'cannot be applied to the non-calling of a witness unless it would be natural for the party to call the witness or the party might reasonably be expected to call the witness'.[82] This is because a legitimate explanation for a failure to call a witness has been found in the circumstance that the uncalled witness is likely to be favourable to the opposing party.[83] Or as Gaudron ACJ, Gummow, Kirby & Hayne JJ observed in RPS v The Queen.[84]
In a civil trial there will very often be a reasonable expectation that a party would give or call relevant evidence. It will, therefore, be open in such a case to conclude that the failure of a party (or someone in that party's camp) to give evidence leads rationally to an inference that the evidence of that party or witness would not help the party's case … and that …:
'where an inference is open from facts proved by direct evidence and the question is whether it should be drawn, the circumstance that the defendant disputing it might have proved the contrary had he chosen to give evidence is properly to be taken into account as a circumstance in favour of drawing the inference.'
[82] Eccles [39]. See also: Payne v Parker [1976] 1 NSWLR 191, 201 - 202 (Glass JA).
[83] Spence v Demasi (1988) 48 SASR 536, 537, 548 (White, Cox & Perry JJ); Ghazal v Government Insurance Office (NSW) (1992) 29 NSWLR 336 (Kirby P, Mahoney JA & Clarke JA); Duke Group Ltd (in liq) v Pilmer (1998) 27 ACSR 1 15 - 16 (McHugh, Gummow, Hayne & Callinan JJ).
[84] RPS v The Queen [2000] HCA 3; (2000) 199 CLR 620, 632 [26] (Gaudron ACJ, Gummow, Kirby & Hayne JJ), quoting Jones (312) (Menzies J).
However, there is no reason to suppose that the evidence of Dr Egesi or Dr Nathan would have been particularly favourably to either party. Both were professionals, medical practitioners, not lay witnesses. There was no reason to suppose that their evidence would not have been available to either party (subject to meeting the hurdles in WCIMAR r 58 and r 59).[85] That being so, another of the relevant conditions for applying the principle in Jones v Dunkel was not satisfied, strengthening the conclusion that there was no basis for drawing the inferences that the Arbitrator did.
[85] Eccles [39].
Ground of appeal 2.1 has been made out.
Ground 2.4 essentially repeats ground 2.1, and is also made out.
It is convenient to deal with this issue of leave in relation grounds of appeal 2.1 and 2.4 at this point. I do not consider that these errors were material to the Decision in the sense that each contributes to it so that, but for the error, the Decision would have been, or might have been, different.[86] As I have observed, the rule in Jones v Dunkel permits an inference, not that evidence not called by a party would have been adverse to the party, but only that it would not have assisted the party.[87] It follows that removing the two inferences erroneously drawn by the Arbitrator does not strengthen the Appellant's evidence. I am not persuaded that, without each inference, the Decision would have been any different.
[86] Bond (353); Brady [15].
[87] Kuhl [64].
Accordingly, I decline leave to appeal in relation to grounds of appeal 2.1 and 2.4.
Ground of appeal 2.3 asserts an error in not drawing a Jones v Dunkel inference against the Respondent in relation to Dr Egesi. The ground recites that it was the Respondent who tendered his report and it was not shown or argued that he was in the 'worker's camp'. However, had the Arbitrator drawn a Jones v Dunkel inference against the Respondent in relation to Dr Egesi, she would have fallen into the errors identified in ground of appeal 2.1. Ground of appeal is not made out, and should not be the subject of leave.

Did the Arbitrator deny the Appellant procedural fairness in relation to the Jones v Dunkel findings?

This is set out in ground of appeal 2.2:
2.2In the alternative to Ground 2.1, the learned Arbitrator denied procedural fairness to the appellant:
a)in failing to give her any opportunity to argue/explain the inapplicability of the Jones v Dunkel inferences in the circumstances of this case; and/or
b)the reasons why the appellant did not lead viva voce evidence from one or more of her doctors, and/or
c)in failing to give the worker any or any reasonable opportunity to apply to re‑open her case and lead such further evidence if necessary
A denial of procedural fairness constitutes an error of law.[88]
[88] Waite (CA) [107].
The general principles in relation to procedural fairness are summarised by French CJ in International Finance Trust Co Ltd v New South Wales Crime Commission:[89]
Procedural fairness or natural justice lies at the heart of the judicial function … It requires that a court be and appear to be impartial, and provide each party to proceedings before it with an opportunity to be heard, to advance its own case and to answer, by evidence and argument, the case put against it. According to the circumstances, the content of the requirements of procedural fairness may vary.
[89] International Finance Trust Co Ltd v New South Wales Crime Commission [2009] HCA 49; (2009) 240 CLR 319 [54]. See also [88] (Gummow & Bell JJ), [141] - 146] (Heydon J); Rowe v Stoltze [2013] WASCA 92 [51] (Newnes JA, with whom Pullin & Murphy JJA agreed).
A decision-maker should not make an adverse finding relevant to a person's rights, interests or legitimate expectations unless the decision-maker has warned of the risk of that finding being made or unless the risks necessarily inheres in the issues to be decided[90] or the finding could not reasonably have been anticipated.[91] That does not mean a decision‑maker is required to disclose to a person to whom procedural fairness must be accorded the decision‑maker's mental processes, provisional views or proposed conclusions before a final decision is made.[92]
[90] Re Refugee Review Tribunal; Ex parte Aala [2000] HCA 57; (2000) 204 CLR 82 [101] (Gleeson CJ, Gaudron, McHugh, Gummow, Kirby, Hayne & Callinan JJ).
[91] Apache Northwest Pty Ltd v Agostini [No 2] [2009] WASCA 231 [218] (Wheeler, Buss & Newnes JJA) (Apache).
[92] Apache [217].
The respondent submits that the Appellant had fair notice that it was open to the Arbitrator to draw a Jones v Dunkel inference from her failure to call either Dr Nathan or De Egesi. This is on the basis that:[93]
(a)in response to the witness statements obtained from Ms Arunkumar, Ms Jones and Ms Bozanich in June 2018, Marks provided a supplementary witness statement dated 8 October 2018, which included hearsay evidence of Dr Nathan;
(b)the Respondent's opening submissions filed prior to the Arbitration hearing explicitly relied on the rule in Jones v Dunkel; and
(c)it was expressly put to Marks in cross‑examination that her evidence in relation to her conversation with Dr Nathan was contradicted by other witnesses and that no report was obtained from him or Dr Egesi because their evidence would not support her case, and she did not offer any explanation as to why evidence was not obtained from them despite this cross‑examination.[94]
[93] Respondent's submissions, par 42.
[94] AAB 382 - 383.
I agree. There was also express reference to Jones v Dunkel in the course of the hearing.[95]The Appellant has not satisfied me that she was denied procedural fairness in relation to the issue of the application of the rule in Jones v Dunkel.
[95] AAB 459.
Even if I wrong in this conclusion, I do not consider that the error would have been material to the decision; that is, I do not consider that had procedural fairness been afforded, it would have made any difference to the outcome.[96] This is because, as set out above ([84]), even if the effect of affording procedural fairness had been that no Jones v Dunkel inference were drawn, I am not persuaded that it would have made a difference to the outcome.
[96] Re Warden P Roth; Ex Parte Cazaly Iron Ore Pty Ltd [No 2] [2011] WASC 343 [26] (Beech J).
Leave to appeal should not be granted in respect of ground 2.2.

Did the Arbitrator err in law in finding that the Appellant experienced symptoms of cervical radiculopathy on 25 August 2017 when she was attempting to open a bottle?

The fifth issue is set out in ground of appeal 4.2:
Further or alternatively, the learned Arbitrator erred in law in making the finding at [208] (which is inconsistent with the finding at [219]), in the absence of any evidence to support that finding and/or without giving adequate reasons. This error also infected the learned Arbitrator's conclusions relating to WCIMA s 5(a) and/or s 5(d) injuries;
The finding at [208] of the Decision is:
I find that Mrs Marks experienced symptoms of cervical radiculopathy on 25 August 2017 when she was attempting to open a bottle.
The finding at [219] of the Decision is:
I find that there was no accident arising out of or in the course of Mrs Marks' employment which caused any injury for the purposes of paragraph (a) of the definition of that term in s 5(1) of the Act. Rather, Mrs Marks experienced the onset of cervical radiculopathy when she was gardening at home on 9 September 2017 and her symptoms continued when she was at work after that date.
The Appellant gave evidence that she had cramp or twinges on the fingers of her right hand when she was opening a Coke bottle on 25 August 2017.[97]
[97] AAB 366 - 368, 465 - 466.
There was a divergence in the evidence as to how these symptoms were to be medically characterised. Professor Sikorski described the Appellant's symptoms as radiculopathy,[98] as did Mr Skinner (symptoms consistent with the diagnosis of a nerve root compromise at the affected levels).[99] Dr Jenkins also appears to do so.[100] Dr Low thought that the Appellant symptoms were from a right elbow common extensor tendinopathy.[101] Mr Wong observed that she may just have been having cramp.[102] Mr Kern thought that the 'opening of the bottle was likely an incidental activity unrelated to her cervical pathology'.[103]
[98] AAB 305.
[99] AAB 138.
[100] AAB 148.
[101] AAB 325.
[102] AAB 297.
[103] AAB 144 - 145.
As there was some medical evidence that the symptoms described by the Appellant when opening the Coke bottle were radiculopathy, no error of law arises.[104] Again, the assertion in this ground goes no higher than an assertion that the fact found by the Arbitrator was found wrongly or on a doubtful basis, or was against the weight of the evidence.[105]
[104] Erceg [31].
[105] Treby [41] - [42], [54]; Atanasoka [21]; Erceg [31]; Brady [5].
As ground of appeal 4.2 does not involve a question of law, I decline to grant leave in respect of it.

Did the Arbitrator err in law in making a finding that the onset of cervical radiculopathy began when the Appellant was gardening at home on 9 September 2017?

The sixth issue is set out in ground 4.1 in the following terms:
4.1The Arbitrator erred in law in making the finding at [209] and [219] that the onset of 'cervical radiculopathy' began when the appellant was gardening at home on 9 September 17, in the absence of any evidence to support that finding and/or without giving adequate reasons. This error infected the learned Arbitrator's conclusions relating to WCIMA s 5(a) and/or s 5(d) injuries.
The paragraphs of the Decision referred to are as follows:[106]
I find that when Mrs Marks was gardening on 9 September 2017 she experienced symptoms of cervical radiculopathy which persisted until she had undergone surgery. I find that those symptoms had progressed to her elbow at the point of her return to work after the weekend of 9-10 September 2017 such that she asked Ms Arunkumar to bandage her elbow. I find that those symptoms had an immediate adverse effect on Mrs Marks' capacity for work.
…
I find that there was no accident arising out of or in the course of Mrs Marks' employment which caused any injury for the purposes of paragraph (a) of the definition of that term in s 5(1) of the Act. Rather, Mrs Marks experienced the onset of cervical radiculopathy when she was gardening at home on 9 September 2017 and her symptoms continued when she was at work after that date.
[106] Decision [209], [219].
The Arbitrator later found that the Appellant's 'degenerative change had been rendered symptomatic by her gardening to such an extent that, as at 12 September 2017, she was already compromised in respect of her ability to perform her duties'.[107]
[107] Decision [222].
The findings set out at [219] of the decision are inconsistent with the finding by the Arbitrator (discussed at [95] ‑ [101]) that the Appellant 'experienced symptoms of cervical radiculopathy on 25 August 2017 when she was opening or attempting to open a bottle'.[108]
[108] Decision [208] also [132].

Again, he was of the opinion that the symptoms experienced by the Appellant were degenerative in origin:[190]
[190] AAB 293 - 297.
I cannot really find any particular injury that has caused the onset of her symptoms. There was spontaneous onset of the symptoms on the 25^th August, 2017 and 9^th September, 2017. On the 12^th September, 2017 she was putting chickens into bags which made her more symptomatic, but I do not particularly believe there was any particular injury. Once she stopped putting the chickens into bags, her symptoms improved.
…
According to her, the mulching episode only caused momentary symptoms of cramp and discomfort in the right hand. She did not complain of any particular arm pain at that stage. Nevertheless, the arm pain seems to have progressed over time going initially distally in the hand and then working its way all the way up to the neck.
…
The diagnosis is possible cervical radiculopathy which has responded to surgery. However, her symptoms are not clear cut and whilst I say it is possible cervical radiculopathy, it is difficult to know which particular nerve is involved. Nevertheless the MRI Scan does show abnormality at C5/6 and C6/7 level and surgery has been helpful to her symptoms.
…
I cannot identify any particular injury that led to the onset of her symptoms. The MRI Scan does show foraminal narrowing at C5/6 and C6/7 which could effect the nerves on both sides and on top of that there is a small super‑imposed 4mm disc herniation at C5/6 on the left side with potential to impinge on the left C6 nerve root. These could all be explained on the basis of underlying degeneration without any specific injury. Disc herniation does not necessarily need to occur as a result of injury. In fact, most of the time people with soft disc herniation wake up with it.
…
It is very possible that a disc prolapse can occur without any specific incident or injury.
…
I think the likely onset of her problem is really related to degeneration. I am not particularly convinced it is related to any particular injury at work or related to the type of work she has been doing.
…
On the balance of probabilities, I think it is more related to underlying generative changes rather than any particular injury.
…
I am not convinced that her work at Coles has contributed to the overall degenerative changes. In fact, people who do sedentary work can have similar problems. On the balance of probabilities, I am not convinced that her work at Coles or previously had contributed to her problem.
…
As mentioned, I think her problem is more related to degenerative changes. Her symptoms initially in my view are not typical of cervical radiculopathy i.e. when she was opening the bottle of soft drink. She may simply have been having cramps.
In summary, the history of the onset of symptoms recorded by Dr Low, Professor Sikorski and Mr Wong closely correlates with the Appellant's evidence as set out at [149] above. There is thus a clear factual foundation for their opinions. Or put in the negative, there is no basis in the evidence to discount their opinions on the ground that the factual foundation on which they were based has not been established in the evidence before the Arbitrator. Professor Sikorski and Mr Wong were of the view that the issues with the Appellant's cervical spine, and the symptoms she experienced, were degenerative in nature. Mr Low did not think the symptoms were even connected to the degeneration. None gave evidence to the effect that on 12 September 2017 the Appellant suffered what could be characterised as a 'personal injury by accident' within paragraph (a) of the WCIMA definition in the sense of some definite or distinct physiological change or physiological disturbance for the worse, which, if not sudden, is at least identifiable.[191] Nor do they give evidence that the was an aggravation or acceleration of a pre-existing injury on 12 September 2017 within par (d) of the WCIMA definition in the sense of the injury being made worse as distinct from simply becoming worse.[192]
[191] May [45] – [48]; Waite (CA) [47], [61], [80]; Ramsay Health Care [28] - [45]; Waite (DC) [143] ‑ [146].
[192] FAI [68]; Ogden [29].
Mr Kern saw the Appellant first on 6 February 2018. I have set out above ([27]) in detail the relevant extracts of his report dated 29 June 2018.
Mr Kern also opined that the Appellant's symptoms are caused by C5/6 and C6/7 spondylosis. However, he was of the opinion that degeneration alone is unlikely to have caused the pathology at the C5/6 and C6/7 levels as he did not see similar degenerative findings at other levels. Rather, in his opinion, it is much more likely that strenuous activities at work have been a major contributing factor. He opines that the disc prolapses at C5/6 and C6/7 worsened on 12 September 2017 when 'she was performing heavy physical activities lifting crates of chicken at work'. However, as set out above ([149]) this is not the Appellant's evidence. This factual basis this does not correlate well with the Appellant's evidence that it was not the lifting of crates of chicken that caused her symptoms, but placing individual chickens in Ziploc bags and closing them. So while Mr Kern's opinion is capable of supporting a finding that the Appellant suffered an injury on 12 September within both pars (a) and (d) of the WCIMA Definition (in the sense set out in at [62] and [63]), the weight of his opinion is weakened by the lack of close correlation with the Appellant's own evidence.
Dr Jenkins' report saw the Appellant on 8 February 2018 and reported the same day.[193] His report of the history of symptoms is somewhat different to the other opinions as there is reference to neck pain in 2016:[194]
Ms Marks developed mechanical neck pain in the context of her work as a Deli Assistant at Coles Gosnells from late 2016. She continued working. In July 2017 she developed initially intermittent symptoms in her radial right hand (thumb and index finger). After two episodes at home she was asymptomatic for some weeks before she first experienced this at work while sealing chicken bags. Her neck, right arm and neck symptoms deteriorated and from September to October 2017 she developed increasing left arm pain in addition. She was initially suspected of having carpal tunnel syndrome and/or tennis elbow and/or a repetitive strain injury of the right upper limb, however treatment for these conditions did not improve her symptoms and in early November 2017 she was found to have significant multilevel foraminal stenoses impinging on the right C6 and C7 nerve roots and also the left C6 nerve root.
[193] AAB 148 - 166.
[194] AAB 148.
He opined in accordance with this history:[195]
6In relation to the first accident of 12 September 2017 are you of the opinion that my client has sustained an injury and/or disease as a result of the work accident and was the employment a significant contributing factor?
In my opinion Ms Marks has most likely exacerbated prior asymptomatic cervical spondylosis at work from late 2016. She described the onset of neck symptoms at work in the context of repetitive manual handling and preparing produce for clients including reaching in and retrieving heavy salad containers, cheese wheels and 'chubs' of meat. She also described hitting her head at least five times over a period of approximately two years on the delicatessen cabinet lids when pulling her head out of the cabinet. Ms Marks did not describe any activity outside her working life which led to symptoms rather her symptoms tended to be better when she was not at work and returned reliably when she was at work. Ms Marks was a somewhat disorganised historian, however with persisting and careful questioning I am satisfied that my history was accurate. I formed no impression that she was attempting to mislead me in any way.
7.In relation to the first accident of 12 September 2017 has my client suffered a recurrence, aggravation or acceleration of any pre‑existing condition and/or disease where the employment was a contributing factor and contributed to a significant degree?
Please see the above. I feel Ms Marks is suffering from an exacerbation of cervical spondylosis and has most likely had radiculopathy, particularly in the right C6 dermatome which appears to be currently somewhat improved. Whether it deteriorates or not remains to be seen. She also has clinical medial and lateral epicondylitis on the right.
[195] AAB 150.
Dr Jenkins opined that the Appellant has most likely exacerbated prior asymptomatic cervical spondylosis at work from late 2016. If accepted, this is a basis for a conclusion that the Appellant suffered an injury within par (d) of the WCIMA definition. However, he bases his opinion in part on a history of 'hitting her head at least five times over a period of approximately two years on the delicatessen cabinet lids when pulling her head out of the cabinet'. This does not correlate well with the Appellant's evidence that, while she had hit her head a number of times over the two years preceding September 2017, it did not hurt, nor cause symptoms.[196] So the weight of Dr Jenkins opinion is weakened by a lack of close correlation with the Appellant's own evidence.
[196] AAB 477.
Mr Skinner reported on 3 July 2018 following a consultation the date of which is not apparent.[197] His records the following history from the Appellant:[198]
[197] AAB 129 - 140.
[198] AAB 130 - 132.
HISTORY OF INJURY
Mrs Marks reported that there had not been a specific injury which led to the cause of her troubles rather a series of incidents.
Mrs Marks reported that she suffered a number of blows to the head in the course of her duties. It was necessary for her to lean into a display cabinet and reach to the front of the cabinet to obtain displayed products as they were being asked for by customers. The cabinets described as 'deep' with the display shelf sloping downwards and away from the access door. It was necessary for Mrs Marks to not only place her arms into the cabinet but also her head and shoulders. She reported that as she exited the cabinet she 'frequently knocked her head' on top of the cabinet. On 'many' occasions the knock removed not only her hat but also her hairnet.
Mrs Marks also reported striking her right elbow from time to time as the walking space between the slicer and the shelf was quite narrow. Mrs Marks also reported that she frequently developed bruises in the region of the right scapula region as she struck her shoulder on the corner of the metal shelf in the same region of the store.
Mrs Marks was unable to recall the number of times each of these incidents had occurred.
…
HISTORY OF THE DEVELOPMENT OF SYMPTOMS
On the 19 July 2017 Mrs Marks reported that she had returned from her annual leave.
She noted no particular troubles at that time, I understand.
In August 2017, whilst attempting to open a Coca-Cola bottle at home, she noted spasm of the right middle and index finger associated with pain. This pain resolved.
On the 9 September 2017 she was attempting to mulch her roses at home when again she noted similar symptoms affecting her right hand. She had been undertaking approximately 2 hours of gardening work at that time. She then stopped the work. Mrs Marks reported that she expected the symptoms to resolve.
On the 12 September 2017 Mrs Marks was at work. She was closing chicken bags. The bags had a Ziploc seal. In order to close the bag, it was necessary to flex the wrist and use a motion of squeezing the index finger and thumb to seal the Ziploc.
Mrs Marks noted cramping in her wrist that time.
Mrs Marks then reported that, over the following 2 weeks, she noted the development of pain when she was obliged to form the pincer grip in her duties at work. Activities such as separating stickers which had been printed became awkward for her.
…
Over time, Mrs Marks noted that her symptoms gradually deteriorated. She noted that her right arm became a problem for her, initially the problem was in the hand, she noted that it progressed to the elbow. Subsequently it moved to her shoulder and neck.
As to the event of 12 September 2017, he opined:[199]
In relation to the… accident of 12 September 2017 are you of the opinion that my client has sustained an injury and/or disease as a result of the work accident and was the employment a significant contributing factor or has my client suffered a recurrence, aggravation or acceleration of any pre-existing condition and/or disease where the employment was a contributing factor and contributed to a significant degree?
It is my view that, based on the history given to me of recurrent striking of the head, neck and shoulder, the 'incident' of the 12 September 2017 was in fact the culmination of the series of injuries sustained in the course of her duties. It is my view, on the basis of the information available to me, that Mrs Marks has suffered an injury as a result of her employment, where her employment had contributed to a significant degree.
[199] AAB 138.
Mr Skinner also bases his opinion on an onset of symptoms from August 2017 first when opening a Coke bottle, then when mulching, and finally at work on 12 September 2017, with the symptoms gradually deteriorating from that point. This is again consistent with the Appellant's evidence set out at [149] above. But he also bases his opinion on a history of 'recurrent striking of the head, neck and shoulder'. This does not correlate well with the Appellant's evidence that, while she had hit her head a number of times over the two years preceding September 2017, it did not hurt, nor cause symptoms.[200] So the weight of Mr Skinner's opinion is also weakened by a lack of close correlation with the Appellant's own evidence.
[200] AAB 477.
At best, the Arbitrator was left with three experts opining in favour of there being an injury for the purposes of the WICMA (each with an opinion weakened by a lack of close correlation with the Appellant's evidence) and three experts opining that there was no such injury (whose opinions closely correlated with the Appellant's evidence). There is no basis to discount the opinions of the experts who opined that there was no injury.
The onus was on the Appellant to prove on the balance of probabilities that she sustained an injury within either par (a) or (d) of the WCIMA definition. The required the Arbitrator to make a finding on the evidence and not assume the existence of a fact.[201] She was required to be actually persuaded that the probability of the fact being true was greater than it not being true.[202] The 'facts proved must form a reasonable basis for a definite conclusion affirmatively drawn of the truth of which the tribunal of fact may reasonably be satisfied'.[203] The Arbitrator must have 'the appropriate degree of confidence in its existence or correctness based on or judged according to reason'.[204] At best, the opinion evidence was that it was equally likely that the cause of the Appellant's symptoms was degeneration unconnected with her work as opposed to being caused by a work related injury in the sense delineated in WCIMA s 5, and no basis for finding the latter to be more probable or likely than not. If anything, the former hypothesis stronger as it the opinions on which it is based correlated more closely with the Appellant's own evidence.
[201] Swick Nominees Pty Ltd t/as Swick Drilling Australia v Norncott Pty Ltd [No 3] [2013] WASC 173 [153] (Allanson J).
[202] Briginshaw v Briginshaw [1938] HCA 34; (1938) 60 CLR 336, 343 (Latham CJ);
[203] Jones v Dunkel (305) (Dixon CJ). Malec v JC Hutton Pty Ltd [1990] HCA 20; (1990) 169 CLR 638, 642 ‑ 643 (Deane, Gaudron & McHugh JJ).
[204] Jones v Sutherland Shire Council[1979] 2 NSWLR 206, 227 (Mahoney JA).
Appellate intervention in relation to such a finding of fact, even in an appeal by way of rehearing, requires the Appellant to demonstrate that the finding is flawed by reference to incontrovertible facts or uncontested testimony, that it is glaringly improbable or contrary to compelling inferences, or that the Arbitrator failed to use, or has palpably misused, her advantage as the trier of fact.[205]I do not consider that the Appellant has established that the Arbitrator much an error of this kind. Rather, even allowing for the errors that I have identified, and taking the Appellant's evidence at its highest, there was a clear basis in the facts for the Arbitrator's ultimate finding that the Appellant failed to establish her claim on the balance of probabilities.
[205] Treby [53]; Fox v Percy [22], [23], [29], [31]; Robinson Helicopter [43]; Badran v Public Transport Authority of Western Australia [2017] WASCA 28 [65] (reasons of the court); Woodley v Woodley [2018] WASCA 149[154] (judgment of the court); East Metropolitan Health Service v Martin [2017] WASCA 7 [99] (reasons of the court).
The review which I have carried out does not persuade me that the Arbitrator's decision should be varied, discharged or otherwise disturbed. Accordingly, it should stand.[206]
[206] Pacific Industrial Co [20] - [26].

Did the Arbitrator demonstrate a reasonable apprehension of bias against the Appellant?

The twelfth issue is set out in grounds 1.2 and 3:
1.2In the alternative to Ground 1.1 above, the learned Arbitrator's conclusion that the worker 'deliberately' minimised her gardening activities (at [177] ‑ [178], [190]) in the face of her finding that the only other contrary evidence came from witnesses who had colluded/collaborated on this issue, gives rise to a reasonable apprehension that an observer might consider that the learned Arbitrator might not have brought an impartial mind to her fact‑finding role.
…
3.Having regard to Ground 1.2, 2.1, 2.2, 2.3 and/or 2.4 above, the learned Arbitrator demonstrated a reasonable apprehension of bias against the worker.
Counsel for the Appellant invited me to consider these grounds only if the appeal was not otherwise successful. [207]
[207] Appellant's submissions, par 38.
A decision of an Arbitrator who is, or appears to be, biased, breaches the rules of procedural fairness and thereby may be set aside based on an error of law.[208]
[208] R v Watson; Ex parte Armstrong [1976] HCA 39; (1976) 136 CLR 248, 262 - 263 (Barwick CJ, Gibbs, Stephen & Mason JJ) (Watson).
In R v Watson; Ex parte Armstrong the High Court expressed the principle to be that 'a judge should not sit to hear a case if in all the circumstances the parties or the public might reasonably suspect that he was not unprejudiced and impartial'.[209]
[209] Watson (262 - 263).
The test to be applied in determining whether a decision of an Arbitrator should be set aside by reason of the appearance of bias, is whether a fair-minded lay observer might reasonably apprehend that the Arbitrator might not have not brought an impartial and unprejudiced mind to the resolution of the question the Arbitrator was required to decide.[210] The observer is taken to be reasonable. The decision maker being observed is taken to be a professional arbitrator whose training and tradition require him or her to discard the irrelevant, the immaterial and the prejudicial.[211] In the WICMA context, the arbitrator must be observed as a someone under an obligation to 'act according to equity, good conscience and the substantial merits of the case without regard to technicalities and legal forms'.[212] Further, in judging whether there is a reasonable apprehension of bias, it should be assumed that the lay observer would base his or her opinion on a fair assessment of the arbitrator's conduct in the context of the arbitration as a whole.[213]
[210] Johnson v Johnson [2000] HCA 48; (2000) 201 CLR 488 [11] (Gleeson CJ, Gaudron, McHugh, Gummow & Hayne JJ) (Johnson); Caratti v Mammoth Investments Pty Ltd (No 2) [2018] WASCA 6 [128] (judgment of the court); Smart v Albuquerque [2011] WASCA 231 [9] (judgment of the court) (Smart).
[211] Johnson [12]; Smart [9]. A person cannot be engaged as an arbitrator unless they are a legal practitioner: WCIMA s 182ZQ(3).
[212] WCIMA s 188(2).
[213] De Alwis v The State of Western Australia [No 2] [2015] WASCA 42 [70] (McLure P, with whom Buss & Mazza JJA agreed).

As to other grounds of appeal mentioned in grounds of appeal 1.2 and 3, I have already observed that ground of appeal 1 is overstated (above [69]). I did not consider grounds of appeal 2.2 or 2.3 involved errors of law. Although grounds of appeal 2.1 and 2.4 involved errors of law, they were mot material.
The finding that the Arbitrator made errors of law in the Decision is not, of itself, a basis for a reasonable apprehension of bias.[214] The existence of the ability to appeal if an error of law is made demonstrates that Parliament anticipated that arbitrators would make errors of law from time to time, which would be corrected on appeal either to this court or the Court of Appeal.
[214] Blenkinsop v Holland [2018] WADC 146 [358] (Gething DCJ).
The fact that the Arbitrator did not accept all the evidence of the Appellant, made adverse credibility findings against her and made findings of fact against her again is not a basis for a reasonable apprehension of bias against the Appellant. Those findings were made in a reasoned and transparent manner based on the information before the Arbitrator, in particular the cross-examination of the Appellant. Moreover, the very purpose of the arbitration process is to make findings of fact as between two parties who are in dispute.
In submissions, counsel for the Appellant draws attention to imbalances in procedural rulings against the Appellant in favour of the Respondent. The rulings against the Appellant were:[215]
(a)to adduce hand written notes made by the Appellant; and
(b)to adduce fresh evidence in the form of a report from Dr Jenkins of 5 December 2018 (after the conclusion of the arbitration hearing).
However, in each case, the reasoning was detailed and transparent,[216] in accordance with long standing authority[217] and not the subject of challenge in this appeal.
[215] Appellant's submissions, par 39.
[216] Decision [75] - [90] (handwritten notes), [129] - [135] (Dr Jenkins report).
[217] Decision [79].
On the other hand, the Appellant says that the Arbitrator:[218]
(a)allowed the Respondent to adduce the Appellant's Medicare records in the course of the hearing; and
(b)failed to apply with rule in Jones v Dunkel in relation to the failure to call Nicole Ladd (there being evidence from the bar table that she was in Singapore on her honeymoon at the time of the hearing).
Again, neither ruling was challenged in the appeal, so the Appellant does not assert that either ruling involved an error of law.
[218] Appellant's submissions, pars 39, 41.
The fact that the Arbitrator made rulings against the Appellant does not, of itself, provide a basis for a reasonable apprehension that the Arbitrator did not bring an impartial or unprejudiced mind to bear on those matters and other matters.[219] Again, it is inherent in the arbitration process, within the WICMA regime, that an arbitrator will be required to make procedural rulings between the parties during that process.
[219] Blenkinsop [357]; MTI v SUL [No 2] [2012] WASCA 87 [14] (judgment of the court).
From my review of the case as a whole, I do not consider that a 'fair‑minded lay observer might reasonably apprehend' that the Arbitrator had not brought an impartial and unprejudiced mind to the resolution of the issues the Arbitrator had to decide.
I accept that grounds of appeal 1.2 and 3 involve an error of law, so leave should be granted. However, the substance of the ground of the ground is not made out so there was no error of law.

What final orders are appropriate?

While the Appellant should have leave to appeal, the appeal should be dismissed.
I will hear from the parties as to costs.

I certify that the preceding paragraph(s) comprise the reasons for decision of the District Court of Western Australia.
JM
Associate
20 MARCH 2020