Zamora v OCS Services Pty Ltd - [2024] WADC 77

JURISDICTION : DISTRICT COURT OF WESTERN AUSTRALIA
IN CIVIL

LOCATION:   PERTH
CITATION:   ZAMORA -v- OCS SERVICES PTY LTD [2024] WADC 77
CORAM:   CURWOOD DCJ
HEARD:   5 MARCH 2024
DELIVERED          :   10 SEPTEMBER 2024
FILE NO/S:   APP 42 of 2023
BETWEEN:   ARTURO ZAMORA
Appellant
AND
OCS SERVICES PTY LTD
Respondent

ON APPEAL FROM:
Jurisdiction              :   WORKERS' COMPENSATION ARBITRATION SERVICE
Coram:   ARBITRATOR CHESWORTH
File Number            :   A108942

Catchwords:

Appeal - Workers' Compensation - Section 213(4) Workers' Compensation and Injury Management Act 1981 (WA) - Slip and fall - Reliability of witness - Procedural fairness - Adequacy of reasons - Whether denial of natural justice is established - Turns on own facts

Legislation:

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

Result:

Leave to appeal refused
Appeal dismissed

Representation:

Counsel:

Appellant	:	Mr J J Sheldrick
Respondent	:	Mr D R Clyne

Solicitors:

Appellant	:	Maurice Blackburn
Respondent	:	Moray & Agnew

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

Amaca Pty Ltd v Werfel [2020] SASCFC 125
Atanasoska v Inghams Enterprises Pty Ltd [2009] WASCA 17
Audino v WA Country Health Service - Wheatbelt [2013] WADC 46
Australian Broadcasting Tribunal v Bond (1990) 170 CLR 321
BHP Billiton Iron Ore Pty Ltd v Brady [2008] WASCA 250
Browne v Browne [2019] WASCA 1
Catholic Education Office of WA v Granitto [2012] WASCA 266
Centex Australasia Pty Ltd v Commissioner for Consumer Protection [2017] WASCA 79
Commissioner for Australian Capital Territory Revenue v Alphaone Pty Ltd (1994) 49 FCR 576
Davie v Manuel [2024] WASCA 21
Day v SAS Trustee Corporation [2021] NSWCA 71
Dearman v Dearman (1908) 7 CLR 549
Defendi v Szigligeti [2019] WASCA 115
DL v The Queen (2018) 266 CLR 1
Dodson v Woolworths Group Ltd [2020] WADC 157
DuluxGroup (Australia) Pty Ltd v Chapple [2023] WASCA 83
Fox v Percy [2003] HCA 22; (2003) 214 CLR 118
Frigger v Frigger [2023] WASCA 103
Gordon v Ross [2006] NSWCA 157
Greenslade v Hiew [2022] WASCA 47
Kennedy Cleaning Services Pty Ltd v Petkoska [2000] HCA 45; (2000) 200 CLR 286
Kuhl v Zurich Financial Services Australia Ltd [2011] HCA 11; (2011) 243 CLR 361
LPDT v Minister for Immigration, Citizenship, Migrant Services and Multicultural Affairs [2024] HCA 12
May v Military Rehabilitation and Compensation Commission (2015) 233 FCR 397
McNamara v The Queen [2021] SASCFC 2
Military Rehabilitation and Compensation Commission v May [2016] HCA 19; (2016) 257 CLR 468
Moyes v Ensco Australia Pty Ltd [2022] WASCA 104
Player v Avery [2022] WASCA 147
River Hill Contracting Pty Ltd v Moore [2023] WASCA 111
Skinner v Broadbent [2006] WASCA 2
Soulemezis v Dudley (Holdings) Pty Ltd (1987) 10 NSWLR 247
Soulos v Pagones [2023] NSWCA 243
Thomas v Van Den Yssel (1976) 14 SASR 205
Velez Pty Ltd v Tudor [2011] WASCA 218
Vines v Australian Securities and Investments Commission (2007) 73 NSWLR 451; [2007] NSWCA 75
Voulis v Kozary (1975) 180 CLR 177
Warren v Coombes (1979) 142 CLR 531
Waterford v The Commonwealth of Australia (1987) 163 CLR 54

CURWOOD DCJ:

Introduction and overview

On 14 December 2021, the appellant, Mr Arturo Zamora, slipped and fell in the course of his employment as a cleaner with the respondent, OCS Service Pty Ltd (OCS). He was working at Westfield Whitford City Shopping Centre. The slip and fall, which was unwitnessed, occurred late at night in a toilet cubicle of the Shopping Centre after it had closed.
Mr Zamora alleged that as a result of the fall he suffered 'soft tissue injuries' to his right shoulder and lower back. Further, as a consequence of his injuries he developed chronic pain, somatic symptoms disorder and depression. He sought the payment of weekly payments and statutory expenses under the Workers' Compensation and Injury Management Act 1981 (WA) (the Act).
OCS admitted that Mr Zamora fell in a toilet cubicle but disputed the extent and severity of the fall. OCS denied that Mr Zamora had suffered any 'injury' within the meaning of the Act as a consequence of the fall.
On 26 April 2023 the dispute as to the payment of compensation proceeded to an arbitration hearing before a Workers' Compensation Arbitration Service arbitrator, Ms D Chesworth (the Arbitrator), in accordance with pt XI div 4 of the Act. The central issue before the Arbitrator was whether Mr Zamora's slip and fall resulted in a compensable injury to his right shoulder and lower back.[1]
[1] Namely whether he suffered an 'injury' within the meaning of s 5(a) the Act, being a personal injury by accident arising out of or in the course of the employment.
The Arbitrator found that:
1.The fall on 14 December 2021 did not result in an injury to Mr Zamora's right shoulder and lower back.[2]
2.Any condition that Mr Zamora asserted he was suffering from was not causally related to the fall on 14 December 2021.
3.If Mr Zamora suffered any incapacity for work, it did not result from any injury he alleges occurred on 14 December 2021.
4.Mr Zamora was not entitled to weekly payments of compensation or any medical expenses.
[2] Arbitrator's reasons [5] (Reasons).
The Arbitrator stated that her findings turned on her assessment of the reliability and credibility of Mr Zamora, in that he was the only witness to the slip and fall and the medical opinions regarding his injuries relied upon his self‑reporting of the incident and his subsequent symptoms.[3] The Arbitrator found Mr Zamora was an unreliable witness.[4]
[3] Reasons [18].
[4] Reasons [49].
In this appeal Mr Zamora contends that the Arbitrator's decision should be set aside and his claim remitted to the Workers' Compensation Arbitration Service for rehearing before a different arbitrator. Mr Zamora seeks these orders, in broad terms, because he says that:
1.the Arbitrator did not accord him procedural fairness during the hearing process in reaching findings as to the reliability of his evidence;
2.the reasons for decision provided by the Arbitrator were inadequate; and
3.the Arbitrator required him to prove the existence of his injuries by an unnecessarily high level of satisfaction and exactness of proof.
In what follows, I will outline the background facts, the relevant statutory provisions, the decision of the Arbitrator and, finally, deal with Mr Zamora's grounds of appeal.

Mr Zamora's employment with OCS, the events of 14 December 2021 and broad overview of Mr Zamora's medical treatment

On 14 December 2021 Mr Zamora was working at Westfield Whitford Shopping Centre.[5] Mr Zamora was working as a cleaner. At approximately 11.00 pm he had a slip and fall in a toilet cubicle.
[5] The reasons of the Arbitrator, the witness statement of Mr Zamora and certain other documents referred to the incident as having occurred at 'Marmion Shopping Centre' but at the appeal hearing the parties accepted that the incident occurred at Westfield Whitford Shopping Centre. This is also corroborated by contemporaneous records including St John Ambulance records.
Shortly after the fall, a photograph was taken showing Mr Zamora lying on his back between the toilet bowel and the cubicle wall. A call was made to St John Ambulance at 23:31:55. An ambulance arrived at the shopping centre and shortly after midnight, Mr Zamora was taken by ambulance to Joondalup Health Campus (Hospital).[6]
[6] Agreed appeal bundle, page 203 (AB). In preparation of the hearing of the appeal, the parties prepared a bundle of documents which contained each party's book of documents for the hearing before the Arbitrator (containing medical and other evidence) together with the Arbitrator's Reasons and a transcript of the arbitration hearing.
Mr Zamora was admitted to the Hospital as a patient and was discharged on 17 December 2021.[7]
[7] AB, page 200.
Mr Zamora was subsequently reviewed and treated by medical practitioners and a clinical psychologist. The practitioners prepared reports for use in the workers' compensation dispute. These practitioners who reviewed and treated Mr Zamora were:
1.Dr Gupta, a general practitioner;
2.Dr Salmon, a pain management specialist;
3.Dr Kain, a medical practitioner, of Corporate Health;
4.Ms Byers, a clinical psychologist;
5.Dr Tan, an occupational physician;
6.Dr Bala, a neurosurgeon;
7.Dr Menon, a pain specialist;
8.Dr Cheng, a consultant psychiatrist; and
9.Dr Silbert, an occupational physician.
The Arbitrator ultimately drew together in her reasons what Mr Zamora told medical practitioners of the circumstances of the incident and the injuries he reported suffering and his symptoms for those injuries. The Arbitrator also made reference to contemporaneous records of paramedics of St John Ambulance and the medical records at the Hospital.
Mr Zamora claimed that as a result of the injuries he suffered in the slip and fall he was totally incapacitated for all work from 15 December 2021. He sought from OCS weekly payments of compensation and the payment of statutory expenses. OCS disputed the extent and the severity of the slip and fall and disputed that Mr Zamora had suffered an injury as alleged by him.

Arbitrator's ruling at the commencement of arbitration hearing that the extent and severity of the fall as asserted by Mr Zamora was in issue and had to be proved by him

In advance of the hearing before the Arbitrator, each party filed bundles of documents. Mr Zamora's bundle included a statement of proposed evidence and a responsive statement. Each party filed pre‑arbitration submissions and objections as to evidence. Mr Zamora objected to a submission made by OCS that his credibility in relation to his version of the incident giving rise to his injuries was in issue. Mr Zamora's objection was that the issue of his credibility had never been raised before and it was unfair to him for OCS to raise it in pre‑arbitration submissions. The Arbitrator dealt with an objection made on behalf of Mr Zamora in her Reasons [8] ‑ [11]. The Arbitrator overruled Mr Zamora's objection that OCS had not prior to the arbitration put into issue Mr Zamora's 'credibility in terms of the accident' and that it was fundamentally unfair for OCS to raise that in advance of the arbitration in its pre‑arbitration written submissions.
The consequence of the Arbitrator's decision is that prior to the commencement of the arbitration, as a consequence of Mr Zamora's objection being overruled, the severity of the fall asserted by Mr Zamora and the injuries he had sustained would be contested and in issue. Accordingly, he could not be taken by surprise by that being an issue. Further, the only witness to the slip and fall was Mr Zamora himself and that OCS' position was to dispute that Mr Zamora had sustained any compensable injury.[8] The arbitration proceeded on that basis. Mr Zamora did not raise any issue in the appeal about any unfairness to him as a consequence of the Arbitrator's ruling before the arbitration commenced that all matters concerning the extent and severity of the fall that he suffered were in issue.
[8] See Reasons [8] - [12].

The issues for determination as defined by the Arbitrator

In her Reasons the Arbitrator defined four issues which required determination in the arbitration being:[9]
1.Whether Mr Zamora slipped and fell as asserted on 14 December 2021.
2.Whether Mr Zamora suffered a personal injury by accident as a result of the slip and fall, and if so, what injury?
3.Whether Mr Zamora's neural sensitivity, somatic symptom disorder and depression are an 'injury' as defined by s 5(c) or s 5(d) of the Act and whether the employment contributed to a significant degree.
4.Whether Mr Zamora has been totally incapacitated as a result of any injury sustained on 14 December 2021 and has an entitlement to weekly payments of compensation and medical expenses.
[9] Reasons [13]. No party contended on the appeal hearing that the distillation of issues by the Arbitrator was flawed.
Neither party raised any complaint about the manner in which the Arbitrator defined the issues for determination.

Hearing before the Arbitrator

Mr Zamora's evidence-in-chief at the arbitration hearing was given in the form of a witness statement and supplementary witness statement. His primary witness statement, which was dated 5 March 2022, relevantly said:
1.My name is Arturo Zamora.
2.I am employed by OCS Services Pty Ltd for around 6 ½ months.
3.I am a cleaner.
4.I work at the Marmion shopping centre.[10]
5.My tasks include cleaning the escalators and the elevator, mopping and washing and polishing the floor. I also do other cleaning related tasks when needed. I don't clean the toilets.
6.I work from 9 pm-1 am Monday to Friday, except on Thursday …
7.I had a fall at work on Tuesday 14 December 2021 at approx.. 11 pm.
8.On the evening of my fall I started work as normal. I cleaned the Woolworths escalators and then mopped the basement below Woolworths. I was doing my usual cleaning duties. I was mopping the floor when I decided to use the toilet.
9.I didn't realise that anything was amiss when I walked into the toilet. As I opened the door to leave the cubicle my left foot slipped and I fell backwards. I landed on the toilet seat and hit my head and fell to the side of the cubicle. I landed on my right arm.
10.I tried getting up but I couldn't get up by myself as the pain in the back was so severe so I used my radio to call help.
11.My supervisor Puspa came to my aid with some other colleagues. A security guard who is also employed by OCS took some photos of the situation while I was still on the floor. They couldn't help me up because of the pain so they called an ambulance.
…
[10] It appears that much of the confusion about the location of the shopping centre arises from Mr Zamora's own witness statement and evidence.
The responsive statement attached a bundle of documents from Centrelink and made comments on various medical reports and confirmed that he still had symptoms from the fall. The statement relevantly concluded: [11]
…
10.I don't understand how Dr Cheng can say that there is no explanation to my symptoms when he has seen reports from the hospital and my doctor saying I have a pain syndrome. This is not in my head. I've had pain since the fall and spent 2 nights in the hospital after the fall. This all started straight after the fall. I have nothing to hide about my past medical history. I was functional before the fall and since the fall I have been in pain. I now have a lot of anxiety and depression because of the pain and what it has done to my life.
[11] AB, pages 602 - 603.
Mr Zamora was cross-examined by counsel for OCS at the arbitration hearing. In cross‑examination, counsel asked Mr Zamora certain questions about the fall. Relevantly Mr Zamora's answers to questions under cross‑examination were as follows:
COUNSEL: Mr Zamora, do you remember the night of your accident?
WITNESS: Yes, I do - - -
…
COUNSEL: Just once you got to the toilet, you finished and you were about to leave. Is that right?
WITNESS: Yes, sir.
COUNSEL: And the door was still closed, was it?
WITNESS: Yes, sir.
COUNSEL: And you then slipped.
WITNESS: Correct, sir.
COUNSEL: And, I think, subsequently the security guard came and took some photos. Page 237, they're on. Have a look at that one, please. Is that a picture of you?
WITNESS: That's me.
…
COUNSEL: and about how long had you been on the floor when that was taken?
WITNESS: For quite a while.
…
COUNSEL: Where's your walkie-talkie - - -
WITNESS: And finally - - -
COUNSEL: - - - in that photo?
WITNESS: Must be on the other side.
COUNSEL: Other side of what?
WITNESS: That thing there. That wall there, sir.
COUNSEL: On the other side of the wall?
WITNESS: yes. Well, there when I called them and - - -
COUNSEL: Well, you say you had it.
WITNESS: - - - I - - -
COUNSEL: Did you keep hold of it?
WITNESS: - - - reached out for - for it and called them in. My call (indistinct) and then when finally I told them my location and they came, it was hard for them to find me because it's a big shopping centre. Finally they came and they saw me there.
COUNSEL: Was the door still open or closed?
WITNESS: The door was open.
COUNSEL: Who opened the door?
WITNESS: WHEN I WAS COMING OUT OF THE TOILET, SIR.
Counsel: You'd already opened the door?
WITNESS: I slipped on something slippery on the floor.
COUNSEL: So you stood up.
WITNESS: I was - - -
COUNSEL: Adjusted your trousers, I assume.
WITNESS: - - - coming out, yes, sir, and I slipped with this foot, my - - -
COUNSEL: Your left foot.
WITNESS; - - - left - - -
COUNSEL: Your left foot slipped.
WITNESS: - - - foot.
COUNSEL: Yes.
WITNESS: Went heading back. I hit the edge of the toilet seat and I was thrown to the side, to the right side.
COUNSEL: All right.
WITNESS: I landed on my right shoulder, sir.
…
(emphasis added)
As may be noted from that exchange, one of the answers given by Mr Zamora to a question of counsel was that he hit the edge of the toilet seat and was thrown to the right side.
Mr Zamora was asked about his prior treatment for depression and the injuries he sustained in the incident. With respect to his injuries, the following exchange occurred:[12]
[12] AB, page 38.
COUNSEL:[13] You've had MRI scans and other scans, nothing seems to be - come up on those to indicate there's anything wrong with you, is there?
WITNESS:I've got my L4 and L5 damaged. I've got intense pain down below my back sir.
COUNSEL:What do you understand is wrong?
WITNESS:Wrong I've got intense pain there due to my accident and I've had no improvement whatsoever --- my right arm has not the same mobility as my left arm. My legs are numb. You know what … I'm going through sir, here? Do you know what I'm going through? Do you know? If you jumped in my body for just one day, you're experienced all this suffering that I'm going through. I've even wanted to commit suicide because this has taken my life away.
My enjoyment, my social activity is going out, my girlfriend, I used to do sports. Nothing! I feel like a man that's … 96 years old, all broken down …
…
[13] Counsel for the respondent.
The witness was then asked about his consultation with Dr Bala, a neurosurgeon who Mr Zamora's GP referred Mr Zamora to:[14]
[14] AB, page 40.
COUNSEL:And he told you after you seemed ---
WITNESS:Went to see - yeah.
COUNSEL:And he told you your spine is very good.
WITNESS:He didn't examine me at all, your Honour. Your Honour, he was sitting on chair looking at me and laughing. For me, he is not a specialist. A specialist is a person that examines you. He was on his chair whole time on his computer looking at me and laughing. He did not even examine on me, not even put one finger on me.
…
WITNESS:For me he was not a specialist.
In all the circumstances, it was put to Mr Zamora in cross‑examination that there was no physical indication or corroboration of his injuries.

The Arbitrator's Reasons for decision

In approaching the question of Mr Zamora's slip and fall and the extent of any injury, the Arbitrator considered the issue of what Mr Zamora was doing before the slip and fall. She then addressed the cause of the slip and fall before determining the extent of it. On each occasion the Arbitrator considered not only Mr Zamora's direct evidence but also what Mr Zamora had reported to medical practitioners as recorded in their reports. I address these aspects of the Arbitrator's decision in the next paragraphs.
The Arbitrator referred to Mr Zamora's evidence that prior to the fall he 'was mopping the floor when he decided to use the toilet'. The Arbitrator then referred to seemingly contradictory evidence in statements contained in medical reports, specifically:
1.Dr Heng Tan in his report of 10 March 2022 which recorded 'on 14 December 2021, Mr Zamora stated he was spot cleaning the escalator, half-way through needing to use the toilet'.[15]
2.Dr Menon in his report of 28 November 2022 recorded 'he was working as a cleaner and cleaning a toilet when he slipped and landed on his right side'.[16]
3.Dr Cheng in his report of 21 December 2022 which recorded 'he stated he was going down the escalator and then he had the urge to go to the toilet'.[17]
[15] Reasons [25].
[16] Reasons [26].
[17] Reasons [27].

With respect to the issue of what caused the slip and fall, the Arbitrator noted the following matters:
1.Mr Zamora's statement did not go into any detail as to what caused the slip and fall. His workers' compensation claim form dated 20 December 2021 recorded that there was 'something slippery on the floor'. Further, on the same date, 20 December 2021 when Mr Zamora attended his GP, his GP, Dr Gupta noted on the first medical certificate 'slipped at toilet'.[18]
2.The Joondalup Health Campus admission plan noted 'patient using toilet, went to stand slipped on water'.[19]
3.Further, the medical admission proforma notes completed by the attending doctor at the Hospital recorded 'noticed slippery object on the floor after he fell'.[20]
4.On 15 August 2022, Dr Silbert recorded 'he reports arising from the sitting position on the toilet in a cubicle when his left foot slipped forwards on something soapy'.[21]
5.On cross-examination Mr Zamora stated 'he had opened the toilet door and his left foot slipped on something slippery'.[22]
[18] Reasons [28].
[19] Reasons [29].
[20] Reasons [30].
[21] Reasons [31].
[22] Reasons [32].
The Arbitrator then addressed the issue of the extent of the slip and fall. The Arbitrator noted the following evidence:
1.In Mr Zamora's statement of 5 March 2022 he stated:[23]
[23] Reasons [33].
I did not realise anything was amiss when walked into the toilet. As I opened the door to leave the cubicle my foot slipped, and I fell backwards. I landed on the toilet seat and hit my head and fell to the side of the cubicle. I landed on my right arm.
2.The St John Ambulance patient care record notes state: 'An unwitnessed fall when getting off the toilet, impacted lower back and right arm' and 'stated did strike back of head'.[24]
[24] Reasons [34].
3.The Hospital's triage nursing assessment records stated 'got off toilet, as stood slipped and fell backwards, striking lumbar back on toilet, also head strike.[25]
[25] Reasons [35].
4.The medical admission proforma notes completed by the consultant and attending doctor recorded 'works as a cleaner in shopping centre, went to the toilet. Opened his bowels, while exiting, slipped and fell backwards, impacted lower back on toilet, impacted right side of head on stall/divider, then fell onto his right arm on the floor?'.[26]
[26] Reasons [36].
5.The Joondalup Health Campus discharge summary recorded a 'slip while exiting bathroom, fell backwards, hitting lower back against toilet, hit right side of head and right arm'.[27]
[27] Reasons [37].
6.On 20 December 2021 Dr Gupta noted on first medical certificate and in his clinical notes after consultation with Mr Zamora that he had 'slipped at toilet'.[28]
[28] Reasons [38].
7.On 10 January 2022, Dr Richard Kain at Corporate Health recorded in his report a history of 'slipped on exiting toilet cubicle - slipped backwards strike lower back on toilet seat and then thrown to side and hit right shoulder on partition'.[29]
[29] Reasons [39].
8.On 1 February 2022, Dr Salmon recorded in his report a history which stated:
[H]e describes an accident at work as a cleaner on 14 December 2021, he emerged from the toilet and slipped landing on his right side. Initial pain was in the right arm region and in the lumbar spine.
9.A report from Ms Jenni Byers to Dr Gupta of 4 February 2022 recorded:[30]
[30] Reasons [41].
[W]hilst at work on 14 December 2021, Mr Zamora slipped whilst in the toilet cubicle. He slipped, fell heavily, hit his back on the toilet and landed on his right shoulder.
10.On 10 March 2022 Dr Heng Tan recorded in his report a history of 'after getting up from the toilet and washing his hands on his way out, he stated that he slipped backwards, his lower back hitting the toilet and landing on his right side'.[31]
11.Dr Bala, neurosurgeon on 14 March 2022 recorded in his report a history of 'went to use the toilet and slipped and struck his back on the floor and onto the commode. It jarred him …'.[32]
12.Dr Silbert in his report of 15 August 2022 recorded a history of:[33]
…he reports rising from the sitting position on the toilet in a cubicle when his left foot slipped forwards on something soapy. He reports then falling backwards with his right low back striking the edge of the toilet seat and bowl and then bouncing and thrown to his right side and landing on his right shoulder against the floor tiles'.
13.On 28 November 2022 Dr Menon, a consultant in the Department of Pain Management at Sir Charles Gairdner Hospital recorded in his report a history that '… he slipped and landed on his right‑hand side'.
14.Dr Cheng in a report of 22 December 2022 recorded:[34]
[C]oming out of the cubicle, he slipped and fell backwards, and he hit his lower back on the edge of the toilet seat and was thrown to the side of the toilet landing on the right side of his shoulder. He then reached for his walkie talkie to try and get his colleagues to come and get him and it took a while.
[31] Reasons [42].
[32] Reasons [43].
[33] Reasons [44].
[34] Reasons [45].

The Arbitrator's findings as to the credibility and reliability of Mr Zamora's evidence

As I have noted, the Arbitrator found Mr Zamora to be an unreliable witness. That finding causes some difficulty for Mr Zamora in the resolution of his appeal. For the reasons that follow I consider that the Arbitrator's Reasons sufficiently set out a basis for making that conclusion. The Arbitrator's Reasons for that finding were described as being 'based on my assessment of Mr Zamora'.[35] The substance of the Arbitrator's finding at [48] of her Reasons is that his left foot slipped forward, and he landed on the toilet seat. Further, he was not thrown or bounced from the toilet seat so as to land on the cubicle floor with any force as to cause injury to his back, right arm, or shoulder.
[35] Reasons [49].
The Arbitrator said of her finding of Mr Zamora being an unreliable witness that this finding was 'also informed' by the following matters set out in the following subparagraphs of her Reasons at [49]:
(a)Mr Zamora's witness statement making no reference to striking his back on the toilet seat and stating 'I landed on the toilet seat and hit my head and fell to the side of the cubicle. I landed on my right arm';
(b)Mr Zamora gave conflicting accounts to doctors as to what he was doing prior to the slip and fall variously describing that he was 'mopping the floor' and 'cleaning a toilet' 'spot cleaning the escalator' and 'going down the escalator';
(c) Mr Zamora's evidence was that he did not clean toilets. Mr Zamora told Dr Menon on 28 November 2022 that 'he was working as a cleaner and cleaning a toilet when he slipped and landed on his right-hand side';
(d)Mr Zamora reporting he 'slipped on water' 'slippery object' 'something slippery' and 'something soapy';
(e)Mr Zamora has variously reported that 'slipped and fell', 'was thrown to the side of the toilet' and 'bouncing and thrown to the right side';
(f)Mr Zamora has variously reported that he 'landed on his arm', 'landed on his shoulder on the floor files', 'struck his back on the floor', 'struck his back on the toilet seat', 'hit his shoulder on the toilet partition', 'hit the back of his head' and 'hit the right side of his head';
(g)Mr Zamora's reliability was further impacted by his failure to disclose his prior history of anxiety and depression to either Ms Byers, clinical psychologist or Dr Cheng, consultant psychiatrist;
(h)Mr Zamora denied taking any medication prior to and at the time of the accident but when pressed, did admit to taking Zopiclone, a sleeping medication, but denied taking citalopram despite Dr Gupta writing a script of citalopram on 8 November 2021;
(i)Mr Zamora became quite argumentative and angry under cross‑examination and deflected questions under cross‑examination by accusing counsel for OCS of lying; and
(j)the Arbitrator found it was inconceivable that Dr Bala, a neurosurgeon, would sit and laugh in Mr Zamora's face during a consultation as was asserted by Mr Zamora.
As such, the findings in that respect could be summarised as being that the Arbitrator found Mr Zamora's evidence to be unreliable and gave express reasons for that finding.

Arbitrator's reasons that Mr Zamora had not suffered any injury

The Arbitrator concluded that Mr Zamora had not established that he had suffered a soft tissue injury or mechanical trauma to his right shoulder/arm or lumbar spine and he had not sustained any personal injury by accident or consequential injuries within the meaning of s 5(c) and s 5(d) of the Act.[36]
[36] Reasons [69] - [70].
In this respect, the Arbitrator noted that Mr Zamora had to bring some evidence of a definite or distinct physiological change of physiological disturbance which, if not sudden, was identifiable as a consequence of the accident.[37]
[37] Reasons [50].
The Arbitrator then summarised the objective evidence of injuries, specifically:
1.The St John Ambulance records noted 'no bleeding, lacerations or bruising. No external injuries noted. Pain on palpitation of elbow. No bulging mass to the back of head, stated did strike back of head'.
2.A CT scan of the pelvis and lumbar spine undertaken at Joondalup Health Campus noted 'no acute fractures or trauma malignment'. Further, an x-ray of the right arm noted that:
the imaged right humerus outlines normally. Glenohumeral and acromioclavicular joint appears to be in normal alignment. No malignment or significant joint fusion at the elbow joint.
An X-ray of the right elbow was reported as 'no displaced fracture is identified' and: [38]
[38] Reasons [56].
if there are ongoing clinical concern regarding an elbow fracture a further radiograph in 7 - 10 days. CT scans of the right shoulders noted no fracture and CT of the right elbow noted no acute fracture was seen around the elbow.
3.On admission to Joondalup Health Campus, Mr Zamora complained of severe lower back pain and right elbow pain and mild right-sided headache. The discharge summary of 17 December 2021 noted 'reviewed by Allied Health, patient independently mobile and functional use of right arm'. The principal diagnosis on discharge was 'back pain'.[39]
[39] Reasons [57].
4.The first medical certificate dated 20 December 2021 issued by Dr Gupta, general practitioner, recorded 'lower back pain, right shoulder arm and forearm pain, pain radiating to b/l legs' and a diagnosis of 'lower back right shoulder arm and forearm injury'.[40]
[40] Reasons [58].
5.CT of the lumbar spine collected on 29 December 2021 recorded 'no evidence of degenerative disease of the lumbar spine'. A MRI of the lumbar spine resulted in 'no acute fractures delineated, no evidence of a fracture of any of the lumbar vertebrae' and a diagnostic ultrasound of the right shoulder on 6 April 2022 recorded 'no convincing acute rotator cuff tear shown on ultrasound'.[41]
6.Dr Tan, occupational physician, noted on 10 March 2022 that 'The lack of any structural injuries confirmed by the investigations to date' and he diagnosed 'soft tissue contusion injury' and later in the report stated 'By default the injury sustained is that of a soft tissue injury'.
7.On 14 March 2022 Dr Bala, neurosurgeon, wrote to Dr Gupta advising that 'Overall the spine is very good - - definitely no surgery is required'.[42]
8.On 15 August 2022 Dr Silbert, in his report, stated 'There is no evidence of any significant internal derangement of the lumbosacral spine of the right shoulder/arm …' and he diagnosed 'acute mechanical trauma to the lumbosacral spine and right shoulder/arm associated with a reported fall whilst at work …'
9.In the same report he stated: [43]
In my opinion all efforts should be directed towards establishment of a clear and unequivocal diagnoses to account for Mr Zamora's reported persistence of symptoms and dysfunction of the lumbosacral spine and right shoulder.
10.On 16 January Dr Tan reviewed Mr Zamora and in his report of 18 January 2023 recorded:
… there is an absence of any significant structural pathology and the diagnosis of the workplace incident can only be described as a soft tissue injury.
[41] Reasons [59].
[42] Reasons [61].
[43] Reasons [62].
The Arbitrator found that there was no objective evidence that Mr Zamora suffered an injury to his back and shoulder. The Arbitrator referred to a lack of bleeding, lacerations or bruising identified by paramedics. Further, radiological investigations did not show any objective evidence of any injury to his lower back, right shoulder, neck or arm.[44]
[44] Reasons [64].
The Arbitrator made reference to diagnoses of soft tissue injury by Dr Silbert and Dr Tan before referring to the fact that both doctors confirmed there was no objective evidence of any physical injuries as a result of the fall on 14 December 2021. The Arbitrator observed that:[45]
… the terms 'mechanical trauma' and 'soft tissue injury' are umbrella terms used to describe the subjective presentation of symptoms where a more specific diagnosis cannot be afforded and are non‑specific in this case as to be of little use in identifying the injury.
[45] Reasons [67].

The Arbitrator's conclusions

The Arbitrator's conclusions were set out at Reasons [93] - [94]:
The slip and fall that Mr Zamora asserts on 14 December 2021 was not witnessed by anyone other than Mr Zamora. The circumstances of the slip and fall and the self- reporting of his pain and psychological symptoms depends on the veracity of Mr Zamora's evidence. All the specialists and treating doctors have been informed of these matters by Mr Zamora and to a considerable extent have uncritically accepted that information and relied upon it when forming their opinions.
I find that Mr Zamora is not a reliable witness. I find that Mr Zamora did not provide accurate details of the slip and fall including the force of the fall nor did he disclose his prior history of psychological issue to the treating doctors and medico legal specialists.

Grounds of Appeal

Mr Zamora advances two grounds of appeal. Ground 1 was framed as follows:
1.The arbitrator erred in mixed fact and law in finding (at [48] and [49]) that the appellant did not contact the toilet bowl with his back or land with any force as to cause injury to his back, right arm, or shoulder, by denying the appellant procedural fairness and failing to provide adequate reasons.
Particulars
(a)The matters in [49](a) - (f)[46] were not:
[46] The matters set out by the Arbitrator at [49(a)] - [49(j)] of her Reasons are set out in [31] above.
(i)the subject of opening or closing submissions by the respondent;
(ii)put to the appellant in cross-examination; or
(iii)put to the parties by the arbitrator before making her determination.
(b)The matters in [49](i) and (j) were not:
(i)the subject of opening or closing submissions by the respondent; or
(ii)put to the parties by the arbitrator before making her determination.
(c)The arbitrator did not address in her reasons:
(i)the respondent's admission that the appellant felt immediate pain in his back, at paragraph 1 of its outline of submissions; and
(ii)the appellant's evidence of severe back pain such that he could not get up following the fall.
(d)the arbitrator's reasons were stated to be:
(i)based on her assessment of the appellant, which she did not elaborate upon; and
(ii)that the appellant was an unreliable witness, which she did not elaborate upon, save to say that the finding was 'also informed by' the matters in sub-paragraphs (a) - (j).
(e)The arbitrator did not articulate how the matters in [49](a) - (j) led to the findings complained of.
Ground 1 raises two alleged errors of law in a single ground of appeal. The first asserted error, being a lack of procedural fairness accorded to Mr Zamora by the Arbitrator, the second alleged error being a failure of the Arbitrator to provide adequate reasons for her decision. With respect to the five separate subparagraphs of particulars, it was not clear which specific particulars were used to support the separate alleged errors of procedural unfairness and inadequate reasons, or if some particulars applied to both asserted errors. Counsel clarified that:
1.Particular (a) to Ground 1 was relied upon as the particulars of the Arbitrator denying the appellant procedural fairness.[47]
2.The particulars at sub-par (b), (c), (d) and (e) all related to the alleged error of law of failing to provide adequate reasons.[48]
[47] Appeal ts 47 - ts 48.
[48] Appeal ts 27 - ts 30.
Ground 2 was stated as follows:
2.The arbitrator erred in mixed fact and law in finding at [69] that the appellant had not established that he suffered a 'soft tissue injury' or any 'medical trauma' to his right shoulder or arm or lumbar spine, by requiring an unnecessarily high level of satisfaction and exactness of proof and failing to give adequate reasons.
Particulars
(a)The arbitrator found (at [68]) that she was not certain what physiological change was encompassed by those phrases when certainty was not required.
(b)The arbitrator did not address whether Dr Tan's phrase 'soft tissue contusion injury' assisted her to understand the physiological change.
(c)The arbitrator did not address whether the phrases were capable of supporting a finding of physiological change, in the broader context of the reports in which those phrases appeared and the other expert evidence available to her.
Counsel for the appellant stated at the appeal hearing that Ground 2 could only succeed if Ground 1 was upheld.[49] Further, if Ground 1 is upheld on the basis of a denial of procedural fairness, the ordinary course would be to order a re‑hearing of the matter.
[49] ts 38 - ts 39.

The requirement for the appeal to involve a question of law

Mr Zamora requires leave to appeal against the Arbitrator's decision. In order to justify a grant of leave, the appeal must concern an issue of law.[50] An appeal involves a question of law when either an error of law, or error of mixed law in fact, is involved.[51] A detailed summary of the legal principles which apply to a grant of leave and what constitutes an error of law is set out in Dodson v Woolworths Group Ltd.[52]
[50] Section 247(2) of the Act.
[51] Catholic Education Office of WA v Granitto [2012] WASCA 266 [53].
[52] Dodson v Woolworths Group Ltd [2020] WADC 157 [17] ‑ [24].
Whether an appeal ground is properly categorised as raising a question of law is, in many cases, a difficult assessment. The distinction between errors of law, errors of fact and mixed errors of law and fact can be elusive. The relevant principles include:
1.An appeal will involve a question of law if the court, tribunal or statutory decision‑maker whose decision is under appeal has made an error of law or an error of mixed law and fact.[53]
2.A failure to give reasons, or adequate reasons, for a decision, may constitute an error of law. This general proposition must, however, be considered in the context of the provisions of s 213(4) of the Act which I refer to in [62] below.[54]
3.A court, tribunal or statutory decision‑maker does not make an error of law merely because the court, tribunal or decision‑maker finds facts wrongly or upon a doubtful basis.[55]
4.A failure to accord procedural fairness arising from a failure to put a party on notice of a fact or issue, when the decision‑maker's evaluation or conclusion of that fact or issue is one that could not have reasonably been anticipated, may be an error of law[56]. In such a case, an appeal court may be able to infer that, if fairly put on notice of that fact or issue, the party might have addressed the fact or issue by way of further evidence or submissions, such that the party may have been deprived of the possibility of a successful outcome.[57]
5.A decision does not involve an error of law unless the error is material to the decision, in the sense that it contributes to the result so that, but for the error, the decision may have been different.[58]
[53] Atanasoska v Inghams Enterprises Pty Ltd [2009] WASCA 17 [20] (Atanasoska).
[54] Velez Pty Ltd v Tudor [2011] WASCA 218 [57] - [70] (Velez).
[55] Waterford v The Commonwealth of Australia (1987) 163 CLR 54; Atanasoska [21].
[56] Davie v Manuel [2024] WASCA 21 [90] (Davie) referring to Commissioner for Australian Capital Territory Revenue v Alphaone Pty Ltd (1994) 49 FCR 576, 591 ‑ 592.
[57] See, for example, LPDT v Minister for Immigration, Citizenship, Migrant Services and Multicultural Affairs [2024] HCA 12 [14].
[58] Australian Broadcasting Tribunal v Bond (1990) 170 CLR 321, 353; BHP Billiton Iron Ore Pty Ltd v Brady [2008] WASCA 250 [15].

The two appeal grounds seem to require the determination of the following issues:
1.Did the Arbitrator deny Mr Zamora procedural fairness by failing to raise with his counsel:
(a)a point of clarification about what his case was on the slip and fall was whether his case was or was not that, after the slip he made contact with the toilet bowl with his back;
(b)that an adverse credibility finding could be made against Mr Zamora as a consequence of the apparent inconsistencies in his evidence which were ultimately found in her Reasons at [49(a)] - [49(f)]; and
(c)that a finding was open to the Arbitrator that Mr Zamora did not land on the floor of toilet cubicle with sufficient force so as to cause injury to his back, right arm or shoulder,
such that counsel could have addressed those issues with the Arbitrator before the arbitration hearing ended.[59]
[59] Procedural fairness limb of ground 1.
2.Did the Arbitrator provide adequate reasons for her conclusion that Mr Zamora:
(a)did not land on the floor with sufficient force so as to cause injury to his back, right arm or shoulder; and/or
(b)was not a reliable witness.[60]
3.Did the Arbitrator:
(a)Require Mr Zamora to prove that an 'injury' was caused in the slip and fall on standard of proof which was higher than proof on the balance of probabilities?
(b)Fail to give adequate reasons for her finding that Mr Zamora had not established that he suffered a 'soft tissue injury' or any 'medical trauma' to his right shoulder or arm or lumbar spine.[61]
[60] Inadequacy of reasons limb of ground 1.
[61] Ground 2.

Ground 1 - analysis

To determine the merits of the grounds of appeal requires the resolution of a number of sub-issues being:
(a)Were the Arbitrator's findings that Mr Zamora:
(i)did not land on the floor with sufficient force so as to cause injury to his back, right arm or shoulder; and/or
(ii)was not a reliable witness,
analogous to findings of fraud or dishonesty, which Mr Zamora's employer had not raised, and, which could not have been contemplated by Mr Zamora by the way in which the arbitration hearing had been conducted?
(b)If those findings were not analogous to fraud or dishonesty is Mr Zamora's true complaint about a lack of procedural fairness really an attack on the Arbitrator's factual findings that Mr Zamora:
(i)did not land on the floor with sufficient force so as to cause injury to his back, right arm or shoulder; and/or
(ii)was not a reliable witness?
(c)In all of the circumstances of the case, what duty if any, did the Arbitrator have, when assessing the credibility of Mr Zamora's evidence on his unwitnessed fall, to disclose what findings were potentially open to the Arbitrator and which she may make on Mr Zamora's case, specifically by reference to the matters set out ultimately at [49(a)] - [49(f)] inclusive of the Arbitrator's Reasons.
(d)Were the Arbitrator's Reasons inadequate by failing to address a submission by Mr Zamora that he felt immediate pain in his back and that he had such severe back pain he could not get up after the fall?
(e)Further, do the various matters raised in [49] of the Arbitrator's Reasons adequately inform Mr Zamora the appellant of the reasoning for the finding that Mr Zamora was an unreliable witness?

Overview of appellant's argument of Ground 1

I will deal first with the procedural fairness complaint of Ground 1. The contention that Mr Zamora was not accorded procedural fairness by the Arbitrator, centres on the Arbitrator's findings at [48] and [49] of her Reasons. The appellant's contention is that the findings at [49(a)] and [49(f)], which influenced the finding that the appellant was an unreliable witness, were not introduced by OCS during either the opening or closing submissions, nor were they subjects of cross‑examination.
Additionally, the Arbitrator did not address these matters with the parties (or invite submissions from the appellant) prior to reserving her decision. Accordingly, the Arbitrator reached the conclusions in paragraphs [48] and [49] without those matters being raised, argued, or submitted by the parties and that was procedurally unfair to Mr Zamora.
Further, the finding at [48] that Mr Zamora did not make contact with the toilet seat before falling to the cubicle floor was not part of his case. Thus, no adverse inference could be (or should have been) drawn against Mr Zamora's reliability as a witness, which the Arbitrator seems to have done at [48] of her Reasons.

Procedural fairness - legal principles

The principles relating to procedural fairness are well settled and have been outlined by the Court of Appeal in a number of cases in recent years including, for example, Davie v Manuel,[62] Defendi v Szigligeti,[63] and Frigger v Frigger.[64]
[62] Davie [83] - [91].
[63] Defendi v Szigligeti [2019] WASCA 115 [45] - [48].
[64] Frigger v Frigger [2023] WASCA 103 [38] - [41].
From those cases, the following general principles may be observed:
1.A court or tribunal is obliged to accord procedural fairness to a litigant. However, that general proposition is only the first step of any analysis. The second step is to identify the content of the requirements for procedural fairness in the specific case.
2.A fundamental requirement of procedural fairness is that a party is given a reasonable opportunity to be heard, in other words, to present their case by evidence, information and submissions.[65]
3.The requirements of procedural fairness are not fixed or immutable. Procedural fairness is directed to avoid practical injustice. Precisely what is necessary to avoid practical injustice will depend upon the circumstances of each given case.
4.The content of procedural fairness will ordinarily need to be understood having regard to the nature of the proceedings. Arbitration disputes under the Act should, for the reasons I set out further below, generally be amenable to being determined efficiently and expeditiously. Provided that a reasonable opportunity to present their case is given to the parties, issues dealt with by an Arbitrator under the arbitration process required by the Act will need to be flexible and take into account the informality of the procedure in the arbitration process under the Act.
[65] Davie [88].
In Davie the Court of Appeal recently made reference to when and in what circumstances a person to whom procedural fairness is owed will be entitled to have brought to their attention critical issues or factors on which the decision is likely to turn. In Davie the court made these observations:
89Generally speaking, in litigation the parties must anticipate combinations and permutations of various findings and adduce evidence and make submissions at the trial on all the potential findings of fact on the issues litigated. Any gap in the evidence on an issue will generally operate to the detriment of the party carrying the burden of proof on that issue.
90A person to whom procedural fairness is owed is, ordinarily, entitled to have brought to his or her attention the critical issues or factors on which the decision is likely to turn so as to give the person an opportunity to deal with them. However, a decision‑maker is not usually 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. The position may be different when the decision-maker's evaluation or conclusion is one that could not have reasonably been anticipated. In this context, the observations of the Full Court of the Federal Court in Commissioner for Australian Capital Territory Revenue v Alphaone Pty Ltd (1994) 49 FCR 576, 591 ‑ 592 are relevant:
Within the bounds of rationality a decision-maker is generally not obliged to invite comment on the evaluation of the subject's case …
The general propositions set out above may be subject to qualifications in particular cases. Two such qualifications (are):
1 The subject of a decision is entitled to have his or her mind directed to the critical issues or factors on which the decision is likely to turn in order to have an opportunity of dealing with it.
2 The subject is entitled to respond to any adverse conclusion drawn by the decision-maker on material supplied by or known to the subject which is not an obvious and natural evaluation of that material.
(footnotes omitted)
In support of Ground 1 the appellant relied upon, amongst other authorities, the decision of Audino v WA Country Health Service - Wheatbelt.[66] In that case, Stavrianou DCJ discussed the principles of procedural fairness as they apply to arbitrations conducted under the Act.
[66] Audino v WA Country Health Service - Wheatbelt [2013] WADC 46 (Audino).
In the case of Audino, an arbitrator hearing a claim for compensation under the Act made a specific finding that the worker, Mrs Audino, was willing to knowingly deceive her employer regarding the circumstances of her injury, being a hernia. On appeal, it was held that that finding was tantamount to a finding of fraudulent or deceitful conduct on the part of Mrs Audino. Further, while submissions before the arbitrator referred to Mrs Audino's credibility being in issue, there was nothing in the employer's submissions to suggest that fraud or deceptive conduct on the part of Mrs Audino was alleged.
During the arbitration hearing Mrs Audino was not cross‑examined in a way to suggest that she had engaged in dishonesty or deceptive conduct. Relevantly, Mrs Audino was not cross‑examined in relation to propositions which arose from the intended evidence of another witness, being a Ms Jakubow. The arbitrator made findings based on the evidence of Ms Jakubow that Mrs Audino sought to have Ms Jakubow conceal the fact that Mrs Audino had asked her not to say anything about failing to report an incident concerning her injury which led to a finding that Mrs Audino was willing to deceive her employer regarding the circumstances of her injury. The facts in Audino are, in my opinion, different from the present matter.
A Judge or arbitrator holds no duty to advise the parties that a witness's evidence is not adequate to make out the alleged claim. However, where a party claiming compensation for injury has been held to have feigned or exaggerated symptoms, and that proposition is not suggested in cross‑examination, or by the other party, that will be a breach of procedural fairness.[67] In this case, OCS's position was that there was no objective evidence of injury and that the symptoms complained of were not consistent with objective symptoms of an injury.
[67] See for example Kuhl v Zurich Financial Services Australia Ltd [2011] HCA 11; (2011) 243 CLR 361 [70] ‑ [75].

Procedural fairness - some further observations

There is no requirement for a Judge or arbitrator to accept evidence that has not been the subject of cross‑examination. Any failure to cross‑examine on a point is merely a factor to be evaluated and weighed together with all other relevant factors in the case in deciding whether or not to accept or reject a witness's evidence on the point in question.[68]
[68] See for example Moyes v Ensco Australia Pty Ltd [2022] WASCA 104 [104].
An example of the rule generally is contained in the case of Thomas v Van Den Yssel.[69] In that case the observation was made that in a personal injury case damage, is always in issue and a plaintiff or applicant knows that a defendant will contend that his injuries do not deserve the sum which the plaintiff has placed on them. Further in such cases the witness must know that the other side will contend that he is not telling the truth and even in some cases that he is deliberately not telling the truth. Further, in order for such a finding to be made, counsel is not obliged to put a question along the lines of 'I put it to you that your evidence is false'.
[69] Thomas v Van Den Yssel (1976) 14 SASR 205, 207.
More broadly, there is no unfairness where a relevant witness has had notice before giving evidence of a matter in issue, or, where material was already in evidence and a witness could have dealt with it but chose not to.[70]
[70] See for example the various cases referred to in this respect in Vines v Australian Securities and Investments Commission (2007) 73 NSWLR 451; [2007] NSWCA 75 [71] which was cited with approval recently in Day v SAS Trustee Corporation [2021] NSWCA 71 [61].
Finally on this issue, a Judge or arbitrator's role in providing information again depends on the situation. A role in providing information to a self‑represented litigant with the object of attempting to overcome procedural disadvantages will be different in a case where a party if legally represented. On either basis there is no duty to formulate or conduct the case for the litigant.
Turning to the procedure of the arbitration process in workers' compensation disputes and the rules which govern them, it is worthwhile noting the following observation made by the Court of Appeal in River Hill Contracting Pty Ltd v Moore, with respect to the resolution of compensation disputes under the Act:[71]
The Workers Compensation and Injury Management Act 1981 … aims to establish a system for resolution of compensation disputes which is timely, cost effective, accessible and in which arbitrated disputes are determined according to their substantial merits with as little formality and technicality as practicable. The length and complexity of the legislative labyrinth which successive amendments to the Act have created challenges the achievement of that objective. Too often, workers compensation disputes seem to become mired in technical procedural arguments, resolved by long and over-elaborate reasons for arbitral decisions which take many months to produce. It is important that those charged with the difficult responsibility of navigating through the legislative maze bear in mind the need to focus on the fair and efficient determination of the substantive merits of the case.
[71] River Hill Contracting Pty Ltd v Moore [2023] WASCA 111 [1].
Section 213(4) of the Act sets out certain requirements as to the content of the reasons for decision an arbitrator is required to give:
(4)The reasons for an arbitrator's decision ‑
(a)need only identify the facts that the arbitrator has accepted in coming to the decision and give the reasons for doing so; and
(b)need only identify the law that the arbitrator has applied in coming to the decision and give the reasons for doing so; and
(c)need not canvass all the evidence given in the case; and
(d)need not canvass all the factual and legal arguments or issues arising in the case.

Was the Arbitrator obliged to foreshadow her findings in [48] and [49] of her Reasons?

The Arbitrator found that Mr Zamora's evidence was unreliable. Having said that, the Arbitrator did not find that Mr Zamora had acted fraudulently or engaged in deliberately deceptive conduct.
The Arbitrator's Reasons need to be read in the context that Mr Zamora was the only witness to the slip and fall incident.
For his claim to succeed, Mr Zamora was obliged to prove, on the balance of probabilities, that he had suffered a 'personal injury by accident' as a result of the slip and fall.
To decide Mr Zamora's claim, the Arbitrator needed to assess not only Mr Zamora's evidence given at the arbitration, by his witness statement and in cross‑examination, but also the instructions he gave to medical practitioners as to the circumstances of the slip and fall and the severity of the fall and the injury (or injuries) he says he suffered by reason of the fall.
The instructions Mr Zamora gave to various medical practitioners after 14 December 2021, including the paramedics who treated him at the scene and the nurses and doctors who reviewed Mr Zamora at the Hospital, were inconsistent in many material respects. Those inconsistencies gave rise to varying accounts of the events that the Arbitrator had to consider.
As may be noted from the Arbitrator's Reasons, the Arbitrator marshalled and considered the relevant evidence before concluding Mr Zamora was not thrown or bounced from the toilet seat as to land on the cubicle floor with any force as to cause injury to his back, right arm, or shoulder. Further he did not suffer 'a personal injury by accident arising out of or in the course of the employment'.
For the reasons that I will turn to, I do not consider that the Arbitrator was required to draw Mr Zamora's attention to inconsistencies between his evidence at the arbitration hearing and the medical reports and contemporaneous medical records.
Mr Zamora submissions on Ground 1 were, in substance, that:
1.The Arbitrator failed to accord Mr Zamora procedural fairness by making adverse findings as to the reliability of his evidence based upon the six matters set out in [49(a)] - [49(f)] that were not raised by the Arbitrator or the respondent at the appeal hearing.[72]
2.It was not part of Mr Zamora's case that he contacted the toilet bowl with his back. Specifically, that contention was not raised in his witness statement and not advanced in written submissions (or oral submissions at the arbitration). Rather, his case, as advanced at arbitration, was that he landed on the toilet seat after slipping. From the toilet seat he fell to the floor.
3.If the Arbitrator had raised with Mr Zamora his back striking the toilet bowl that question or issue would have been answered by Mr Zamora (or on his behalf) that it was not part of his case and it was not relevant to his reliability as a witness because it was not part of his case.
4.There was no link that the Arbitrator could draw between the findings in [49(a)] ‑ [49(f)] and his evidence being unreliable.
5.Statements attributed to the appellant in various medical reports should have been put to the appellant in cross‑examination (or by the Arbitrator if not in cross‑examination) if adverse findings were likely to be made by the Arbitrator relying on those matters to the extent that they were inconsistent with the evidence led at the trial or the presentation of his case generally.
6.The reliability of Mr Zamora's evidence based upon those matters also had to be reviewed by the Arbitrator in the context that there was a concession (or no challenge) that Mr Zamora felt pain in his back when he landed on the floor of the cubicle.
[72] A corollary of that submission is that no 'procedural fairness' warning was required for the findings at [49(g)] ‑ [ 49(j)].
As may be noted from the general principles I have outlined, the critical question to identify is the content of the requirements of procedural fairness for the case in question. As noted, the fundamental requirement of procedural fairness is that a party is given a reasonable opportunity to be heard, in other words, to present their case by evidence, information and submissions.
In an arbitration under the Act, where both parties are represented by legal practitioners, an arbitrator would not ordinarily be required to disclose to a litigant a provisional view the arbitrator may have formed, or the arbitrator's mental processes or proposed conclusions, for any decision making. The exception to this general proposition is where the arbitrator's evaluation or conclusion is one that could not have reasonably been anticipated by the litigant.
An example of a situation where a conclusion by an arbitrator could not have reasonably been anticipated by the litigant is illustrated by the case of Audino where the arbitrator made a finding, in effect, of fraudulent concealment of an injury when no such case had been advanced by the employer.

Before turning to the specific factual matters raised by Ground 1, I will make some general observations about how the arbitration hearing was conducted.
Mr Zamora and his legal representatives knew at the commencement of the arbitration that the extent and severity of Mr Zamora's fall in the toilet cubicle (and whether that fall caused an injury) was in issue. As with many arbitration hearings under the Act, the Arbitrator and parties were faced with numerous documentary records and medical reports. Based upon the appeal book utilised in the appeal, the Arbitrator was presented in advance of the arbitration with almost 550 pages of medical reports and records, witness statements and legal submissions. The time spent in the hearing was less than one day. At the time of reserving her decision the Arbitrator said she would have 'to go away and read all the documents and … consider what (counsel) have said … (and also read) the witness statements'.[73]
[73] AB, page 61.
As I have noted, the medical reports and records contained various inconsistencies about what Mr Zamora had said as to the lead up to the fall, the circumstances of the fall and of the symptoms of his injuries. Mr Zamora did not attempt to deal with the various inconsistencies ultimately identified by the Arbitrator in his own evidence or by submissions. This could only be construed as a forensic decision.
Mr Zamora's objection raised at the commencement of the arbitration hearing that OCS had not put into issue his 'credibility in terms of the accident' was not accepted by the Arbitrator. The Arbitrator's Reasons make clear that the circumstances and severity of the fall was in issue and should not have taken Mr Zamora by surprise.
That ruling made clear to Mr Zamora that he was required to prove his case and that no concession could be relied upon to prove any factual matter required to be proved by him. Namely, any deficiencies in his evidence or his case could lead to a conclusion that he had not discharged the burden of proof he bore.
OCS highlighted various inconsistencies in Mr Zamora's case and the reliability of his reporting of matters to doctors in its pre‑hearing written submissions. One example was that Mr Zamora had told his treating psychologist, Ms Byers, and the respondent's psychiatrist, Dr Cheng, that he had no history of psychological symptoms during his consults with them. That, according to the respondent, was shown to be wrong by an AAT decision which the appellant provided with his responsive statement and which contained evidence that Mr Zamora had experienced symptoms of depression and anxiety since 1998 and had been taking antidepressive medication.[74]
[74] AB, page 81, par 3 - reference was also made to the AAT decision by the Arbitrator at her Reasons [11].
It was not reasonable for Mr. Zamora to assume, in preparing for and conducting the hearing, that inconsistencies in his account of events would not be addressed unless specifically pointed out, despite the presence of multiple medical reports and records submitted by him that contained inconsistencies in symptom reporting and descriptions of the slip and fall incident.
I do not consider that Mr Zamora could hold a legitimate expectation that the Arbitrator would point out or address inconsistencies in the medical and other evidence, or warn that his evidence might be considered to be unreliable, if he did not seek to address or explain these apparent inconsistencies, even if OCS's counsel did not cross examine him about them. I now turn to the specific factual matters raised in Ground 1 upon which it is said it was procedurally unfair for the Arbitrator to make findings which were adverse to Mr Zamora.

Mr Zamora's back hitting the toilet bowl

In advancing the procedural fairness limb of Ground 1, Mr Zamora drew attention to the second sentence of [48] and [49(a)] of the Arbitrator's Reasons which, for completeness, I will set out in full:[75]
48.I find that as Mr Zamora stood up after using the toilet his left foot slipped forwards and he landed on the toilet seat. I further find that Mr Zamora did not contact the toilet bowl with his back when he landed on the toilet seat. Nor was he thrown or bounced from the toilet seat as to land on the cubicle floor with any force as to cause injury to his back, right arm, or shoulder.
49.Mr reasons for finding this are based on my assessment of Mr Zamora. I find Mr Zamora is an unreliable witness and my finding as to this is also informed by the following matters.
(a)In his statement Mr Zamora makes no reference to striking his back on the toilet seat. Mr Zamora states 'I landed on the toilet seat and hit my head and fell to the side of the cubicle. I landed on my right arm.'
…
[75] Nine further matters were described in [49(b)] - [49(j)], (see [31] above).
To place the conclusions reached by the Arbitrator at [48] and [49] in context, in the earlier part of her Reasons, the Arbitrator had reviewed Mr Zamora's evidence and the medical records which were relevant to the circumstances of and the severity of the fall in the toilet cubicle.
Mr Zamora's primary witness statement, which stood as his evidence‑in‑chief,[76] at par 9 describes the slip as causing him to fall backwards. He said he landed on the toilet seat, hit his head and fell to the side of the cubicle landing on his right arm. The Arbitrator considered this version of the slip and fall in her Reasons at [20].
[76] See [19].
As may be noted from my summary of the Arbitrator's decision, various of the medical reports relied upon in the arbitration refer to Mr Zamora saying that his back hit the toilet bowl.[77] The Arbitrator considered this version of events in her Reasons, for example, at [39] (the history seemingly relayed by Mr Zamora to Dr Kain) and at [41] (the history seemingly relayed by Ms Byers, clinical psychologist).
[77] See for example [29(3)], [29(4)], [29(7)], [29(9)] and [29(13)] above.
The evidence elicited in cross‑examination, was in my view, ambiguous about Mr Zamora's fall, but, on one reading, it could also be construed as his back having hit the toilet bowl.[78]
[78] See [21] above.
Putting to one side the second sentence in [48] of the Reasons about Mr Zamora's back not hitting the toilet bowl, a key finding to the decision reached by the Arbitrator is contained in the final sentence of [48] - that Mr Zamora did not land on the cubicle floor with any force such as to cause injury.
The second sentence of [48] of the Arbitrator's Reasons, that, Mr Zamora did not contact the toilet bowl with his back, makes a finding, that the fall did not occur on a version of Mr Zamora's reporting that his back did make contact with the toilet bowl/toilet seat, such version being contained in:
1.Contemporaneous medical records - see above at [29(2)], [29(3)], [29(4)], [29(5)] and [29(7)].
2.Later reports from medical practitioners as to his contended injuries - see above at [29(9)], [29(10)], [29(12)] and [29(13)].
3.On one reading of Mr Zamora's answers to questions in cross‑examination by counsel for OCS.[79]
[79] See [86] above.
Whilst [49(a)] states that Mr Zamora made no reference in his witness statement about striking his back on the toilet seat, from a reading of the Reasons in their entirety, the evident purpose of [49(a)] ‑ [49(f)] was to highlight conflicting accounts Mr Zamora reported to medical practitioners after the incident.
The complaint in ground 1 that the Arbitrator seemingly criticised Mr Zamora's witness statement (and thereby his evidence) for not mentioning that his back touched the toilet bowl, when that was not actually part of his case, does not, in my opinion, have any real basis.
Notwithstanding that Mr Zamora's case at the arbitration hearing was that he landed on the toilet seat before falling, the Arbitrator still had to consider other versions of the circumstances of the fall which emerged from the instructions Mr Zamora gave to doctors and the contemporaneous records. Mr Zamora's compensation claim was based on a fall that no one saw, so it was important for the Arbitrator to carefully review his evidence and be persuaded to the requisite standard of proof of how the fall happened, the severity of the fall and what injuries, if any, were caused by the fall.
The finding at [48] that Mr Zamora's back did not make contact with the toilet bowl does not appear to have had any real significance in the Arbitrator's resolution of the case. The Arbitrator's finding in [48] went on to say that Mr Zamora was not thrown or bounced from the toilet seat to the cubicle floor with any force as to cause injury to his back, right arm or shoulder. In effect, that finding is that he fell from the toilet seat to the cubicle floor, but not with sufficient force to cause the claimed injuries. Mr Zamora's criticisms of the Arbitrator's comments about Mr Zamora's back not making contact with the toilet bowl do not give rise to an error of law. I do not consider that the Arbitrator was obliged to raise the inconsistencies between the version summarised in [87] about his back making contact with the toilet bowl/toilet seat and the version in his witness statement that he landed on the toilet seat, hit his head and fell to the side of the cubicle.

Was the Arbitrator obliged to foreshadow and raise with Mr Zamora the matters contained at [49(a)] ‑ [49(f)] of her Reasons

I have already commented on the matters stated by the Arbitrator at [49(a)] of her Reasons in [82] - [92] above. With respect to each of the matters outlined by the Arbitrator at [49(b)] ‑ [49(f)], as I understood the appellant's argument, the various conflicts and inconsistencies highlighted by the Arbitrator could not, of themselves, give rise to a conclusion of him being an unreliable witness. I deal with this in the limb of Ground 1 dealing with inadequate reasons.
The various findings in [49(a)] ‑ [49(f)] were open to the Arbitrator in the course of assessing and marshalling the evidence given during the arbitration. As noted, significant inconsistencies emerged in Mr Zamora's versions of reporting the incident and its symptoms to medical practitioners.
I do not consider that the Arbitrator was obliged to point out the inconsistencies between Mr Zamora's evidence‑in‑chief, the instructions he had given to doctors and the contemporaneous medical records. Further, the Arbitrator was not required to disclose to Mr Zamora, as a litigant how, taken either individually or collectively, those matters may inform the Arbitrator's ultimate decision. The Arbitrator was not privy to Mr Zamora's instructions. At the time of the hearing, the Arbitrator could not have been expected to have considered the various permutations in the evidence in the same depth that the parties themselves had in their preparation of the case for a final hearing.[80] Rather than the Arbitrator holding a duty to inform Mr Zamora of what findings she may make when marshalling the contradictory evidence, it was open to Mr Zamora to give evidence himself of the apparent inconsistencies in his case and, to the extent that he thought they could be cleared up or reconciled, he could have given evidence on those matters. Mr Zamora could also have attempted to address the inconsistencies in his case by submissions.
[80] See [75] above as to the Arbitrator's concluding comments at the time of reserving her decision.
The arbitration was conducted on the clear assumption that all matters were in issue concerning the extent of Mr Zamora's fall and any injuries he suffered from that fall. This is clearly stated in the Arbitrator's Reasons, particularly at [1] - [8].
Read fairly, the matters referred to by the Arbitrator at [49(a)] ‑ [49(f)] (inclusive) highlighted inconsistencies in the reporting of events by the appellant. The Arbitrator's findings that those inconsistencies reflected adversely on Mr Zamora when assessing the reliability of his evidence were reasonable and something Mr Zamora, as a party in an adversarial process, could have reasonably anticipated. This was not a case which was similar to the fact situation in Audino where the Arbitrator made findings tantamount to fraud where no such contention had been raised by the employer.
In my opinion it was open to the Arbitrator to make the findings that she made at [49(a)] ‑ [49(f)] (inclusive) of her Reasons without having to inform Mr Zamora what those findings may be or that he should address those issues by other evidence or submissions. Mr Zamora had an opportunity to present his case by evidence, information and submissions. The fact that inconsistencies within the evidence were not addressed by him, even though not raised by the Arbitrator during the hearing, in my view does not lead to a conclusion that the arbitration hearing was procedurally unfair to him.
Taking into account all matters, I do not consider the Arbitrator was obliged during the hearing to draw to Mr Zamora's attention the findings she was inclined to make at [48] and [49(a)] ‑ [49(f)] (inclusive) of the Reasons. The first limb of Ground 1 relying on a failure by the Arbitrator to accord procedural fairness is not made out. There is no error of law as contended by Mr Zamora.

Ground 1 - Inadequacy of reasons

As I have noted, the alleged error of inadequacy of reasons was rolled into the same ground of appeal as the denial of natural justice and procedural fairness. I set out the general principles as to the adequacy of reasons in the next paragraphs.

Legal principles - Inadequacy of reasons

In DL v The Queen, the plurality said:[81]
The content and detail of reasons 'will vary according to the nature of the jurisdiction which the court is exercising and the particular matter the subject of the decision'. In the absence of an express statutory provision, 'a judge returning a verdict following a trial without a jury is obliged to give reasons sufficient to identify the principles of law applied by the judge and the main factual findings on which the judge relied'. One reason for this obligation is the need for adequate reasons in order for an appellate court to discharge its statutory duty on an appeal from the decision and, correspondingly, for the parties to understand the basis for the decision for purposes including the exercise of any rights to appeal.
(footnotes omitted)
[81] DL v The Queen (2018) 266 CLR 1 [32].
Similarly, Nettle J (dissenting in the result) said:[82]
Since parties must be able to see the extent to which their cases have been understood and accepted, a trial judge will ordinarily be expected to expose his or her reasoning on points critical to the contest between the parties. This applies both to evidence and to argument. If a party relies on relevant and cogent evidence which the judge rejects, the judge should provide a reasoned explanation for the rejection of that evidence. If the parties advance conflicting evidence on a matter significant to the outcome, both sets of evidence should be referred to and reasons provided for why the judge prefers one set of evidence to the other. Similarly, while a judge is not required to deal with every argument and issue that might arise in the course of a trial, if a party raises a substantial argument which the judge rejects, the judge should refer to it and assign reasons for its rejection. And in providing reasons, the judge is required to make apparent the steps he or she has taken in reaching the conclusion expressed, for reasons are not intelligible if they leave the reader to speculate as to which of a number of possible paths of reasoning the judge may have taken to that conclusion. Failure sufficiently to expose the path of reasoning is therefore an error of law.
(footnotes omitted)
[82] DL v The Queen [131].
It has been noted that these passages emphasise that what is required of reasons in a given case depends on the particular contests between the parties and the factual findings necessary to resolve those contests.[83] The question of the adequacy of reasons in any given case necessarily incorporates this contextual inquiry.
[83] See McNamara v The Queen [2021] SASCFC 2 [82].
Further principles to evaluate the adequacy of reasons are as follows:
1.The content of reasons will be dependent on the nature of the jurisdiction.[84]
2.In the context of appellate review of the adequacy of reasons, the function of an appellate court is to determine not the optimal level of detail required in reasons for a decision but rather the minimum acceptable standard. The adequacy of reasons is not to be judged as against a standard of perfection. The question is whether the reasons attained the minimum acceptable standard. In that context, a minimum requirement has been identified as being that the reasons be given in a form that will enable the losing party properly to understand the grounds on which the case was lost, and will not frustrate the losing party's right of appeal.[85]
3.Both the losing party, and the appellate court, must be able to distinguish whether a mistake of law or fact was involved. The interested party must be provided their right to appeal in order to uphold natural justice.[86]
4.The provision of inadequate reasons does not automatically constitute an error of law and a ground of appeal. Appellate intervention on the grounds of inadequate reasons for decision will only occur when the inadequacy relates to a material aspect of the case.[87] In this respect in Gordon v Ross[88] Basten JA (Hodgson and Bryson JJA agreeing) said:[89]
As is frequently the case in relation to an appeal by way of re‑hearing, a complaint of lack of adequate reasons tends to obscure the real ground of complaint. Thus, if the real complaint is that no finding has been made, the question of reasons is irrelevant. There is no obligation to give reasons for a finding which has not been made. The gravamen of that complaint, whether right or wrong, must be that no finding has been made in circumstances where there was an obligation to address the issue. On the other hand, if a finding has been made, but is not supported by the evidence, there is little substantial benefit to an appellant to complain of inadequate reasons: on a re-hearing, it would generally be necessary for the Court hearing the appeal to consider the evidence and determine for itself whether it was adequate to support the finding made.
[84] DuluxGroup (Australia) Pty Ltd v Chapple [2023] WASCA 83 [46].
[85] Soulos v Pagones [2023] NSWCA 243 [418] (authorities omitted).
[86] Soulemezis v Dudley (Holdings) Pty Ltd (1987) 10 NSWLR 247, 280 (McHugh JA) (Soulemezis); Skinner v Broadbent [2006] WASCA 2 [38] (Skinner).
[87] Amaca Pty Ltd v Werfel[2020] SASCFC 125 [23].
[88] Gordon v Ross [2006] NSWCA 157.
[89] Gordon v Ross [81].
If the correctness of the finding is material to the outcome, the absence of adequate reasons may then constitute error sufficient to require a retrial.
Where an appeal is by way of rehearing, an appellant ordinarily identifies error in a factual finding. An arbitrator is obliged to articulate the reasoning process that links the facts and law to justify the ultimate decision.[90] If a finding is made without any reasoning to support it, it may not be possible to discern error from a review of the evidence. In Greenslade v Hiew[91] the Court of Appeal recently stated that this is an explanation of why inadequacy of reasons does not, of itself, necessarily amount to an appealable error.[92] Rather, an appeal court will only intervene when the inadequacy or insufficiency in the reasons is such as to give rise to a miscarriage of justice.
[90] Velez [60].
[91] Greenslade v Hiew [2022] WASCA 47.
[92] Greenslade v Hiew [48] - [49].
The content of reasons for decision required from an arbitrator is also, in my opinion, informed by the objects of the Act. Namely, the Act is designed to promote expedition, simplicity, and transparency.[93] Section 3(1) of the Act provides:
[93] Dodson v Woolworths Group Ltd [168].
3.Purposes
The purposes of this Act are -
…
(c)to provide for the resolution of disputes under this Act; and
(d)to make provision for the hearing and determination by the dispute resolution authorities of disputes between parties involved in workers compensation matters in a manner that is fair, just, economical, informal and quick.

An appellate court may consider what can legitimately be inferred from the reasons as a whole. Whether the reasons are adequate will depend upon the circumstances of the case and that matters which arose for consideration.[94]
[94] Browne v Browne [2019] WASCA 1 [80] (judgment of the court); Player v Avery [2022] WASCA 147 [102].

Analysis of appeal Ground 1 relating to inadequacy of reasons

As I have noted, the aspects of ground 1 contending that the Arbitrator did not give adequate reasons for her decision are set out in particulars (b) ‑ (e) to the ground. When read together, it is argued that the Arbitrator's reasoning relied on her assessment of the appellant, which she did not explain in sufficient detail. Mr Zamora's argument, as I understood it, was that the Arbitrator found the appellant to be an unreliable witness but did not provide reasons for this finding, except to say it was influenced by the ten issues listed in [49(a)] ‑ [49(j)].
Whilst I will deal with each of the particulars in turn, for the reasons that follow, I consider that read fairly, each of the matters in [49(a)] ‑ [49(j)], when taken together, provide a sufficient basis for the Arbitrator's finding that Mr Zamora was not a reliable witness. Generally, a finding that a witness' evidence is not reliable may only be set aside where the credit-based finding is flawed by reference to incontrovertible facts, uncontested testimony, is glaringly improbable or contrary to compelling inferences. That condition does not exist in this case. The Arbitrator properly assessed and weighed all relevant evidence before reaching her conclusion as to Mr Zamora's lack of reliability. I return to this issue in [123] ‑ [124] below.
As I have referred to in the aspect of my reasons touching on procedural fairness, whilst [48] of the Arbitrator's Reasons sets out the central findings as to the slip and fall, [49] states that the findings are based on the Arbitrator's assessment that Mr Zamora is an unreliable witness.
That finding in the second sentence of [49] of the Arbitrator's Reasons, read fairly, is that Mr Zamora is an unreliable witness because of the Arbitrator's assessment of his evidence and by reason of:
1.Conflicting accounts in his evidence, the examples of which are contained in [49(a)] ‑ [49(f)] inclusive.
2.Mr Zamora's failure to disclose a prior history of anxiety and depression to his clinical psychologist, Ms Byers, or consultant psychiatrist Dr Cheng ([49(g)]).
3.Mr Zamora's denial about taking any medication prior to the accident, but, when later pressed in cross‑examination he did admit to taking a sleeping medication but denied taking Citalopram despite receiving a script for it on 8 November 2021 ([49(h)]).
4.Mr Zamora becoming argumentative and angry under cross‑examination and accusing OCS's counsel of lying to him ([49(i)]).
5.The Arbitrator finding that it was inconceivable that a neurosurgeon, Mr Bala, would laugh in Mr Zamora's face during a consultation as he stated in cross‑examination ([45(j)] (see further [23] above for an extract of the cross-examination in that respect).
Any criticism of the content of the Reasons in [48] ‑ [49] must not overlook the last sentence of [48] where the Arbitrator found that Mr Zamora did not land on the cubicle floor with sufficient force so as to cause injury to his back, right arm or shoulder. The conclusion reached by the Arbitrator of the extent of the force on which Mr Zamora fell to the floor was also reached in her assessment of the objective evidence of the injury which is set out later in the Arbitrator's Reasons, specifically at [50], [54] ‑ [64], [67], [88] and [90].
In these paragraphs of her decision, the Arbitrator analyses the ambulance and Hospital records and radiological investigations which ultimately lead to her conclusion that Mr Zamora did not suffer a soft tissue injury. I now turn to the specific matters in the particulars to ground 1.

Ground 1 - particular (b)

Particular (b) concentrates on the findings made by the Arbitrator at [49(i)] and [49(j)] which relate to:
1.Mr Zamora being argumentative during cross‑examination and deflecting questions; and
2.his evidence being inconceivable that the neurosurgeon, Dr Bala, would sit and laugh in his face during a consultation as Mr Zamora stated in cross‑examination.[95]
[95] In this respect the aspects of the cross‑examination concerning Dr Bala are set out at [24] above.
Whether Mr Zamora became argumentative and angry under cross‑examination was a matter for the Arbitrator. This was a matter upon which the Arbitrator had the advantage of being the trier of fact at first instance.[96] Any challenge of this finding reflects a 'natural limitation' an appellate court faces when relying mainly on the record. Specifically, it highlights the disadvantage that appellate courts face compared to the original arbitrator in assessing witness credibility and the overall 'feel' of the case, which cannot be fully understood just from reading the transcript.[97] I consider that the Arbitrator has given adequate reasons for her findings in [49(i)] and [49(j)].
[96] Fox v Percy [2003] HCA 22; (2003) 214 CLR 118; Centex Australasia Pty Ltd v Commissioner for Consumer Protection [2017] WASCA 79; see [123] below.
[97] See [123] below.

Ground 1 - particular (c)

With respect to the complaint in particular (c), during the course of the appeal hearing, counsel for the appellant said that the inadequacy of reasons related to particular (c) was that the Arbitrator did not address in her reasons that the appellant felt immediate pain in his back and that pain was so severe that he could not get up following the fall.
In her Reasons the Arbitrator did make reference to Mr Zamora feeling back pain after the fall. Specifically, at [21] the Arbitrator considered Mr Zamora's evidence that he was unable to get up following the fall 'as the pain in his back was so severe …'. The Arbitrator also said at [23] that Mr Zamora's evidence was that he continues to have pain in his lower back and walks with a cane.
The Arbitrator then referred to the references to Mr Zamora's back pain in the contemporaneous records including Hospital records (at Reasons [35]). The Arbitrator did weigh Mr Zamora's evidence and complaints about suffering lower back pain in the aspect of her reasons touching on whether Mr Zamora suffered a personal injury by accident. Specifically:
(a)the St John Ambulance patient care notes made no reference to bruising and referred to pain on palpation of elbow;[98]
(b)that on admission to the Hospital Mr Zamora underwent a CT scan of the lumbar spine and it was noted that there was no acute fractures or traumatic malalignment;[99]
(c)the discharge notes from the Hospital which recorded that on admission Mr Zamora was complaining of severe lower back pain and that the principal diagnosis on discharge was 'back pain';[100]
(d)Dr Gupta's medical certificate which made reference to lower back pain;[101]
(e)a CT of the lumbar spine on 29 December 2021 which stated that there was 'no evidence of degenerative disease of the lumbar spine'. Further that on 11 January an MRI of the lumbar spine recorded 'no acute fractures delineated, no evidence of a fracture of any of the lumbar vertebrae';[102]
(f)Dr Tan's report on review on 10 March 2022 was that the 'lack of any structural injury is confirmed by the investigations to date' and that 'by default the injury sustained if that of a soft tissue injury';[103]
(g)Dr Silbert's, occupational physician, opinion on review on 15 August 2022 that there was 'no evidence of any significant internal derangement of the lumbosacral spine …' and that 'all effects should be directed towards establishment of a clear and unequivocal diagnosis to account for Mr Zamora's reported persistence of symptoms and dysfunction of the lumbosacral spine and right shoulder';[104] and
(h)the diagnosis by Dr Tan that there was a 'disproportionate degree of pain and limitations, on the background of a normal CT and MRI of the lumbar spine … [and] clinically, the features on examination does not correlate to a subacromial pain syndrome. By default, there is an absence of any significant structural pathology, and the diagnosis of the workplace incident can only be described as a soft tissue injury'.[105]
[98] Reasons [55].
[99] Reasons [57].
[100] Reasons [57].
[101] Reasons [58].
[102] Reasons [59].
[103] Reasons [60].
[104] Reasons [62].
[105] Reasons [63].
The Arbitrator at Reasons [64] ‑ [70] concluded that Mr Zamora had not sustained a personal injury by accident. Whilst some of those aspects are challenged in ground 2, the contention in particular (c) that the Arbitrator did not address in her Reasons the submissions that the appellant felt immediate pain in his back and that he could not get up following the fall is not made out. The Arbitrator considered that evidence. Further, those factual matters and the weight the Arbitrator placed on them form part of her reasoning. The Arbitrator did not find Mr Zamora had suffered an injury ostensibly because there was no objective evidence to support that an injury had occurred beyond the subjective reporting of injury by Mr Zamora. I consider that the Arbitrator has addressed in her Reasons Mr Zamora's case that he felt immediate pain in his back and that pain was so severe that he could not get up following the fall.

Ground 1 - particulars (d) and (e)

Particulars (d) and (e) of Ground 1 assert that the Arbitrator's reasons are inadequate because there was no elaboration of why Mr Zamora was an unreliable witness save to say that the finding was 'also informed by' the matters in [49] subparagraphs (a) ‑ (j) and the Arbitrator did not articulate how they led to the findings.
Read fairly, the reasons disclose why the Arbitrator found Mr Zamora to be an unreliable witness.
In Centex Australasia Pty Ltd v Commissioner for Consumer Protection[106] the Court of Appeal made the following observations as to credibility factual findings:
[106] Centex Australasia Pty Ltd v Commissioner for Consumer Protection [99] - [100].
The proper role of an appellate court reviewing findings of fact made by a court (or tribunal) at first instance has been essayed in many cases. In Australia the most authoritative statement of the principles governing such a review is to be found in the decision of the High Court of Australia in Fox v Percy. For present purposes it is sufficient to succinctly enunciate propositions developed by the plurality in their reasons:
(a)all appeals are creatures of statute therefore the ambit of any appeal will turn upon the proper construction of the statute creating the right of appeal;
(b)while on the one hand the appellate court is obliged to 'give the judgment which in its opinion ought to have been given in the first instance'[107] on the other, it must, of necessity, observe the 'natural limitations' that exist in the case of any appellate court proceeding wholly or substantially on the records;
[107] See Dearman v Dearman (1908) 7 CLR 549, 561.
(c)these limitations include the disadvantage that the appellate court has when compared with a tribunal at first instance in respect of the evaluation of the credibility of witnesses and of the 'feeling' of a case which cannot be gleaned from the reading of the transcript;
(d)furthermore, an appellate court does not typically get taken to or read all of the evidence taken at trial, with the result that a tribunal at first instance has advantages that derive from considering the entirety of the evidence, and reflecting upon that evidence over a longer interval;
(e)within these constraints an appellate court is obliged to conduct a real review of the trial and is not excused from the task of 'weighing conflicting evidence and drawing [their] own inferences and conclusions, though [they] should always bear in mind that [they have] neither seen nor heard the witnesses and should make due allowance in this respect';[108]
(f)in general an appellate court is in as good a position as the court at first instance to decide on the proper inference to be drawn from facts which are undisputed or, which having been disputed, are established by the findings of the court;[109]
(g)in deciding the proper inference to be drawn the appellate court will give respect and weight to the conclusion of the court at first instance but once having reached its own conclusion will not shrink from giving effect to it;[110]
(h)the mere fact that a trial judge necessarily reached a conclusion favouring the witnesses of one party over those of another does not, and cannot, prevent the performance by a court of appeal of the functions imposed on it by statute;[111]
(i)in some cases incontrovertible facts or uncontested testimony will demonstrate that the conclusions of fact made by the court at first instance are erroneous even when they appear to be, or are stated to be based on credibility findings;[112]
(j)if the decision at trial is glaringly improbable or contrary to compelling inferences the appellate court is not relieved of its statutory functions by the fact that the trial judge has, expressly or implicitly, reached a conclusion influenced by an opinion concerning the credibility of witnesses;[113]
(k)while appellate deference to the decision of a trial judge can be justified by the advantage of assessing the demeanour of witnesses when giving their evidence, more recently caution has been expressed with respect to the weight properly given to assessments of demeanour as compared to an assessment of credibility based upon objectively established facts, contemporary documents and the apparent logic of events.[114]
Generally speaking, a trial judge's credibility‑based findings will not be reversed on appeal unless it is demonstrated that such findings are flawed by reference to incontrovertible facts or uncontested testimony, or are glaringly improbable or contrary to compelling inferences.
(footnotes omitted)
[108] Dearman v Dearman.
[109] Warren v Coombes (1979) 142 CLR 531, 551.
[110] Warren v Coombes.
[111] Fox v Percy [28].
[112] Fox v Percy citing Voulis v Kozary (1975) 180 CLR 177.
[113] Fox v Percy [29].
[114] Fox v Percy [30] ‑ [31].
In my opinion, the combination of the matters referred in [49(a)] ‑ [49(j)] combined 'with her overall assessment of Mr Zamora' led to the Arbitrator's finding that Mr Zamora was an unreliable witness. The matters in [49(a)] ‑ [49(j)] are examples for why the Arbitrator found Mr Zamora to be an unreliable witness in a context in which the incident was an unwitnessed fall. I consider those matters collectively give adequate reasons for the finding made that Mr Zamora's evidence was unreliable.
Account must also be taken of the Arbitrator's ultimate conclusion at [93] ‑ [95] that Mr Zamora did not provide accurate details of the slip and fall, including, the force of the fall, nor, did he disclose his prior history of psychological issues to treating doctors and medicolegal specialists.
When these matters are combined with the obvious advantage that the Arbitrator had in considering Mr Zamora evidence and her findings that he was argumentative and angry under cross‑examination and deflecting questions under cross‑examination by accusing counsel for OCS of lying, I consider that the Arbitrator has provided adequate reasons for her conclusion that Mr Zamora was not a reliable witness and that he did not land on the floor of the toilet cubicle with such force as to cause injury.

Conclusions on the merits of Ground 1

Whilst it is clearly the case that an arbitrator giving inadequate reasons for a decision may constitute an error of law and, plainly, a denial of procedural fairness or natural justice is an error of law, these labels cannot be used to mask challenges of fact. The Arbitrator's decision was underpinned by a factual finding that Mr Zamora was not a reliable witness. He gave contradicting versions of the events which led to the fall to his doctors. He also gave contradictory evidence of the extent of his injuries to doctors and medical professionals. It was open to the Arbitrator, as the trier of fact with the clear advantage of seeing Mr Zamora give his evidence, to make those findings. I consider that the Arbitrator's findings are properly reasoned.
For all of these reasons, Ground 1 does not raise an error of law.

Is it necessary to decide Ground 2?

In light of the concession made by counsel for the appellant concerning Ground 2 not falling for consideration if Ground 1 was not made out (see [42] above), I will only make some short observations on Ground 2. For the reasons that follow Ground 2 does not raise an error of law.

Does Ground 2 raise an error of law?

In [15] and [16] of her Reasons the Arbitrator outlined the burden and standard of proof required to be discharged by Mr Zamora. Namely, he had the burden of establishing his case and the standard of proof was on the balance of probabilities. Further it was not necessary for there to be an exactness of proof in order to find a fact proven provided there is sufficient evidence that can be afforded weight to support findings of fact or for a reasonable inference to be drawn.
The Arbitrator also noted at Reasons [17] that, with respect to matters of expert evidence, it remained for the party carrying the onus of proof, in this case Mr Zamora, to ensure that the expert evidence is explained in a manner that supports the finding agitated for.
After setting out these introductory comments the Arbitrator stated at Reasons [18] that in order to find that the information provided by Mr Zamora to doctors is reliable she had to accept his evidence and that the assessment of the reliability of his evidence was a multifactorial task involving a consideration of contemporary materials, objectively established facts and the apparent logic of events.
In her Reasons at [50], the Arbitrator made reference to the High Court decision in Military Rehabilitation and Compensation Commission v May.[115] In that case the plurality made reference to the definition used by Gleeson CJ and Kirby J in Kennedy Cleaning Services Pty Limited v Petkoska[116] that an injury as that term is used in its primary sense is 'something … can be described as a sudden and ascertainable or dramatic physiological change or disturbance of the normal physiological state, it may qualify for characterisation as an 'injury' in the primary sense of that word'.[117]
[115] Military Rehabilitation and Compensation Commission v May [2016] HCA 19; (2016) 257 CLR 468.
[116] Kennedy Cleaning Services Pty Ltd v Petkoska [2000] HCA 45; (2000) 200 CLR 286 (Kennedy).
[117] Kennedy (300), [39]; see also at (298) - (299), [35], (300) - (301), [40].
In Military Rehabilitation, Gageler J made the following observations:
1.Every ailment can at some level be described as an alteration from the functioning of a healthy mind or body however not every ailment can be described as an injury in the ordinary sense. At least in the case of a physical injury, to suffer an injury is more than just to experience the onset of disfunction.
2.An injury may be established on the basis of an account by a claimant of the disturbances to his or her body or mind, without the necessity for a diagnosis of a recognised medical condition, or corroborating pathology or medical opinion, but whether or not the evidence of a claimant will be sufficient, if it is not supported, corroborated or confirmed by independent medical opinion or pathology will be a matter for the judge's (or arbitrator's) satisfaction on the evidence in each particular case.[118]
[118] Military Rehabilitation and Compensation Commission v May [78], [79] referring to May v Military Rehabilitation and Compensation Commission (2015) 233 FCR 397, [212] Although the Full Federal Court's decision was overturned by the High Court, this part of the Full Federal Court's decision was not criticised on appeal and was adopted by Gageler J in his reasons.

Ground 2 is, in effect, an attempt to challenge a factual finding made by the Arbitrator at [69] of her Reasons.
As I have noted the Arbitrator found that there was no objective evidence of any injury to Mr Zamora's right shoulder or arm or lumber spine or back generally. In making that finding, the Arbitrator did not require the proof of those matters by what is referred to in the appeal ground as 'an unnecessarily high level of satisfaction and exactness of proof'.
The Arbitrator addressed Dr Tan's phrase 'soft tissue contusion injury' in her Reasons at [60] and [66]. The Arbitrator observed at [66]:
On 10 March 2022 Dr Tan's diagnosed 'soft tissue contusion injury'. He later states, 'By default the injury sustained is that of a soft tissue injury.' On 16 January 2023 Dr Tan again reviewed Mr Zamora and states, 'The subjective portrayal of his symptoms and the clinical findings on examination does not concur with a specific diagnosis(es). In the setting of a soft tissue injury, where imaging studies are normal, there is a high suspicion magnification of symptoms and poor/effort reliability in his clinical examination participation'.
The Arbitrator, as I have noted at [35] ‑ [37] above, made a finding that mechanical trauma or soft tissue injuries are umbrella terms to describe the subjective presentation of symptoms where a more specific diagnosis could not be afforded.
In other words, those terms are broad descriptions to categorise symptoms which in this case were personal to Mr Zamora where a more precise diagnosis was not possible because no objective evidence of a physical injury existed.
By that wording, the Arbitrator was expressing a view that beyond Mr Zamora saying that he had symptoms of pain or injury, no medical diagnosis could pinpoint the exact nature of the injury.
On the face of the Reasons the Arbitrator has not required proof of any issue beyond the normal standard of on the balance of probabilities.
The Arbitrator was simply making the observation at [68] and [69] of her Reasons that no objective evidence existed which could lead to a conclusion beyond Mr Zamora's subjective reporting of symptoms of any injury to his shoulder, neck, arm or back.
The assessment of Mr Zamora's symptoms and whether they constituted an injury in the sense used in the Act and as defined in various cases including Military Rehabilitation and Compensation Commission v May was open to the Arbitrator. The Arbitrator was not satisfied on the evidence that Mr Zamora had suffered an injury.
The Arbitrator gave adequate reasons for her assessment that Mr Zamora had not suffered a 'personal injury by accident' as a result of the slip and fall at [50] - [90] of the Reasons.
In my opinion, Ground 2 does not raise any error of law. As its highest, Ground 2 seeks to challenge a factual finding.

Conclusion and final orders

The appeal does not raise a question of law. Leave to appeal is refused. The appeal is dismissed. I will hear the parties as to costs.

I certify that the preceding paragraph(s) comprise the reasons for decision of the District Court of Western Australia.
LM
Associate to Judge Curwood
10 SEPTEMBER 2024