Toll Transport Pty Ltd v Medwin - [2018] TASSC 15

[2018] TASSC 15

COURT: SUPREME COURT OF TASMANIA

CITATION: Toll Transport Pty Ltd v Medwin [2018] TASSC 15

PARTIES:  TOLL TRANSPORT PTY LTD
  (T/AS TOLL TASMANIA) (ACN 006 604 191)
  v
MEDWIN, Logan William Ryan

FILE NO: 544/2017
JUDGMENT

APPEALED FROM: Toll Holdings Limited v M (Ref No 1/2017)
[2017] TASWRCT 2

DELIVERED ON:  10 April 2018
DELIVERED AT:  Hobart
HEARING DATE/S:  3 July 2017
JUDGMENT OF:  Wood J

CATCHWORDS:

Workers Compensation – Determination of claims – Jurisdiction of courts, tribunals, commissions and boards – Workers Rehabilitation and Compensation Tribunal (Tas) — Referral to Tribunal – Tribunal determined that a reasonably arguable case did not exist – Whether findings of Tribunal inconsistent – Whether evidence of plausible potential causes inconsistent with liability – No error of law.

Workers Rehabilitation and Compensation Act1988 (Tas), s 81A.
St Helen's Oysters Pty Ltd v Coatsworth [2007] TASSC 90, 17 Tas R 43 at [15], applied.
Aust Dig Workers Compensation [3050]

REPRESENTATION:

Counsel:
             Appellant:  K Read SC
             Respondent:  S Taglieri
Solicitors:
             Appellant:  Page Seager Lawyers
             Respondent:  Slater and Gordon

Judgment Number: [2018] TASSC 15
Number of paragraphs: 35

Serial No 15/2018
File No 544/2017

TOLL TRANSPORT PTY LTD (T/AS TOLL TASMANIA) (ACN 006 604 191)
v LOGAN WILLIAM RYAN MEDWIN

REASONS FOR JUDGMENT WOOD J

10 April 2018

This appeal concerns a disputed claim for workers compensation and a determination made by the Chief Commissioner of the Workers Rehabilitation and Compensation Tribunal, Mr R Webster, pursuant to s 81A of the Workers Rehabilitation and Compensation Act 1988 ("the Act"). The Chief Commissioner determined that he was not satisfied that the employer had a reasonably arguable case concerning the claim, and dismissed the employer's reference to the Tribunal. To now succeed on appeal the employer, being the appellant, must show that the learned Chief Commissioner made an error of law in his determination: s 63(1) of the Act. If the evidentiary material before the Chief Commissioner necessarily leads to a conclusion that a reasonably arguable case did exist, then he would have made such an error: St Helen's Oysters Pty Ltd v Coatsworth [2007] TASSC 90, 17 Tas R 43 at [15].
In October 2016, the respondent, Logan Medwin, lodged a claim for workers compensation supported by a medical certificate. He was employed as a fitter/welder in the appellant's Burnie workshop. He claimed compensation for an injury or condition that occurred on 7 October 2016 when he had been "abused, discriminated and assaulted verbally by a co-worker". He added that this conduct had been on-going since February. He stated that "on the Friday [referring to 7 October] I couldn't take it any more as I had an anxiety attack and more which is stated in worker's comp med cert". He asserted the occurrence caused "work related stress and anxiety and producing signs of depression".
The workers compensation medical certificate provided by Dr Waheed Al Tamimi stated that she examined the respondent on 7 October 2016 and his presenting symptoms were "stress, anxiety", and that her provisional diagnosis was "stress and anxiety, work related", and that the "injury or disease" is "consistent with the stated cause", as provided in the claim.
The employer, the appellant, disputed the claim and referred it to the Tribunal for determination pursuant to s 81A of the Act. There were three grounds for disputing liability as follows (the first paragraph merely stating a fact that the "worker has made a claim for a psychological condition"):
"(2)The Employer disputes that the worker has suffered an injury, which is a disease and to which his employment contributed to a substantial degree, as required by s 25(1)(b) and s 3(2A) of the Act.
(3)The Employer says that compensation is not payable under the Act in respect of the worker's disease, which is an illness or disorder of the mind, which has arisen substantially from reasonable action taken in a reasonable manner to discipline or counsel the worker and thus fell within a defence pursuant to s 25(1A)(a) of the Act.
(4)The Employer says that compensation is not payable in respect of the worker's disease, which is an illness or disorder of the mind, and which has arisen substantially from reasonable administrative action taken in a reasonable manner by the employer in connection with the worker's employment, s 25(1A)(c) of the Act."

The s 81A hearing

At the hearing, evidentiary material before the Commissioner included the workers compensation claim and supporting medical certificate provided by Dr Al Tamimi. The appellant tendered statements from the Operations Manager of the employer, Mr Von Bibra, and Mr John Dicker, the employee said to have verbally abused the respondent on 7 October 2016. In his statement, Mr Dicker conceded that during an incident on 7 October the respondent was within hearing range when Mr Dicker described him as "the fuckwit in the doorway", and when passing the respondent he may have said something like "get out of the fucking way".
The only other evidentiary material tendered by the appellant was a report from consultant psychiatrist, Dr Frank Chow, dated 22 December 2016, prepared at the request of the insurer. Dr Chow noted that the respondent told him that he went off work after an incident on 7 October 2016 when his "colleague verbally swore at him indirectly and he found out that his personal belongings were destroyed". The respondent told Dr Chow that this incident occurred against a background of escalating bullying and harassment behaviours over a number of months from a particular colleague. The problem started after the respondent became a union delegate in February 2016; he experienced bullying and harassment from non-union members and his "boss was not responsive to the situation that he was in" and ignored the behaviour.
In his report, Dr Chow stated that the "event on 7 October 2016 was the causative factor of the developed condition and the event was the most significant factor in the development of the condition". As noted, concessions were made by Mr Dicker in his evidence about words he uttered on 7 October. While he denied any involvement in destruction of the respondent's property, this was not significant, noting a lack of evidence before the Chief Commissioner as to whether another employee may have been involved in such conduct.
Of significance to the appeal is evidence of the presence of other stressors in the respondent's life. The records of Dr Al Tamimi were provided to Dr Chow and were referred to by Dr Chow in his report. The medical record on 24 November 2016 stated that the worker's younger brother committed suicide a few months before, his mother had been in Spencer Clinic on and off, and his baby daughter had been born four months before. Having referred to these records, Dr Chow noted in his report:
"I am unable to confidently comment on the impact [sic] any other non-work related factors that might be contributing to his developed condition due to him not being willing to discuss any of his personal information during assessment today.
Not to trivialise his difficult workplace experiences, I would suspect his brother's suicide, mother's condition and his relationship would have an impact on his psychological state."
The appellant also tendered a short report from Dr Al Tamimi, dated 16 December 2016, which responded to specific queries and supplemented the information provided in the medical certificate. It referred to the respondent's attendance on 7 October 2016 when he had been "looking very anxious and stressed". It referred to the fact that the respondent had been a union representative since February 2016 and that some co-workers had been targeting him by abusing him verbally, and he felt he was discriminated against. It noted that the respondent had suffered from panic disorders for several years since 2009 and he had been on medications which usually keep his condition under control.
In Mr Von Bibra's statement he gave an account of his understanding of some of these stressors regarding the death of the respondent's brother earlier in 2016, and the birth of his child. Mr Von Bibra's statement also referred to dealings with the respondent and an occasion earlier in 2016 when the respondent had sought union intervention in relation to an allegation of harassment of him by Mr Von Bibra and another employee of the appellant. The incident related to them requiring that the respondent wear his work-provided clothing and safety gear appropriately. The respondent was prone to tucking his trousers into his socks allowing sparks to drop down into his boots. He was asked repeatedly to cease that practice, and it was said by Mr Von Bibra that the respondent "took offence ... and approached the AMWU to intervene on his behalf". This evidence has significance to grounds 1-3 of the appeal.

The Chief Commissioner's determination

It was argued before the learned Chief Commissioner that the history provided to the general practitioner, Dr Tamimi, with regard to his pre-injury mental state had significance. It was argued that when compared with the history provided to Dr Tamimi, a degree of unreliability could be seen in the history provided to Dr Chow. In particular, Dr Chow stated in his report that: "Mr Medwin said he has no previous medical problem and no prior psychiatric diagnosis or treatment before the incident in October. He did state he had a period of anxiety when his brother passed away in April but he did not need to seek any help." It was argued at the s 81A hearing that inconsistency in the history provided to the two medical practitioners pointed to the unreliability of the worker's history generally, and a weakness in the claim.
The Commissioner set out the approach to be taken to disputed facts at a s 81A hearing:
"13… it was submitted by counsel for the employer that there was a degree of unreliability about the worker's history and I was referred to the history provided by the general practitioner when compared to that provided to Dr Chow in relation to the worker's pre-injury mental state. It was therefore possible that there were non-vocational issues which might be causative factors giving rise to the worker's condition. It was conceded by counsel for the employer that the non-vocational factors could not be said to be causative (given what Dr Chow said about them) but they were matters that suggested there was a degree of unreliability in the history provided by the worker. Making findings with respect to facts that may well be disputed and then how those findings affect the reliability of the worker's history are precluded in an application of this nature which concerns a preliminary determination that results in interim orders.
14I am mindful of the test to be applied in applications under s81A of the Act. The test was expressed by Evans J in St Helens Oysters Pty Ltd v Coatsworth [2007] TASSC 90 at [10] in the following terms:
'On the face of s81A, a reasonably arguable case will exist concerning the liability on the employer to pay a worker if it is reasonably arguable on the material available in relation to the claim or identified deficiencies or weaknesses in the claim that, following a contested hearing it may be rejected.'
15That case also concerned a claim for 'stress, anxiety, depression'. As to claims of that nature his Honour said at [14]:
'It is notorious that the genesis for conditions such as stress, anxiety and depression may be multifaceted. The causes may be many and varied and it can be very difficult to identify the most significant causative factor. In the context of litigation, a final determination as to the existence of such a condition and the causative role of any factor, almost invariably turns upon the adjudicator's assessment of the veracity and reliability of the complainant. Accordingly, when a worker claims to suffer from a condition of this nature in circumstances where there are a variety of potential causes for the condition, an employer may show a reasonably arguable case concerning liability by providing evidence of plausible potential causes that are inconsistent with liability'."
The approach to be taken to s 81A hearings is well-established, and the matters of principle as outlined by the Commissioner are uncontentious and are not the subject of criticism on appeal.
The learned Commissioner noted the matters conceded by the appellant, including the incident on 7 October 2016 and the words uttered by Mr Dicker. He noted that the opinions of Dr Chow and the general practitioner, in her certificate, linked the cause of the worker's condition to the event or events of 7 October 2016.
The Commissioner's concluding reasons addressed whether there was "evidence of plausible potential causes that are inconsistent with liability" and provided that "as to the event or events the worker complains about on 7 October 2016 the employer has not adduced any evidence or plausible potential cause inconsistent with liability". He noted that while the employer is successful with respect to grounds 2 and 3 (the defences of administrative action), ground 1 of the reference (relating to the cause of the "injury") fails as the employer has not discharged the onus of proof which it bears: Lamont v MRD Supermarkets Pty Ltd [2016] TASSC 16, 24 Tas R 234 at [10]. The passage in Lamont specifically referred to by the Chief Commissioner states:
"Because s 81A(2)(b) requires an employer to provide evidentiary material, without which it could not succeed in s 81A proceedings, it must follow that the employer bears an onus of proof in such proceedings: Skilled Group Limited v Anning [2015] TASSC 18. See also GIO Australia Limited v Lovell [2000] TASSC 75 at [13]."

Grounds of appeal

The grounds of appeal are as follows:
"1The Tribunal erred in law in finding in [21] that a reasonably arguable case did not exist concerning the worker's claim after finding in [10] and [21] that grounds 2 and 3 of the referral were made out. The Tribunal determined at [21] that 'Although the employer is successful with respect to grounds 2 and 3, ground 1 of the reference fails as the employer has not discharged the onus of proof which it bears…' and that as a result of ground 1 of the reference failing, it 'follows that the Tribunal cannot be satisfied that a reasonably arguable case exists concerning the workers claim.'
2The Tribunal erred in law in that the only determination that was reasonably open to the Tribunal having found that the Appellant was successful with respect to grounds 2 and 3 of the reference was that a reasonably arguable case did exist concerning the Respondent's claim.
3The Tribunal erred in law in that the only orders that were reasonably open to the Tribunal having found that the Appellant was successful with respect to grounds 2 and 3 of the reference were that:
aThe Appellant was not liable to pay compensation by way of weekly payments to the Respondent from the date of the Tribunal's determination; and
bThe Appellant is not liable to pay the cost of any benefits payable under Division 2 of Part VI of the Act in respect of the injury to the Respondent from the date of the Tribunal's determination.
4Failing to determine whether it was reasonably arguable that following a contested hearing the claim might be rejected because it might not be shown that the incidents of 7 October 2016 contributed to substantial degree to the worker's 'stress anxiety and depression'. That determination ought to have been made because there was evidence before him of plausible and potential causes that were inconsistent with liability."
The first three grounds of appeal are tied to grounds 2 and 3 of the referral, concerning the defences of reasonable action and reasonable administrative action by the appellant, and it is convenient to consider them together. Ground 4 relates to an issue raised in ground 1 of the referral that if the worker has suffered an injury which is a disease, it has not been shown that his employment contributed to a substantial degree, as required by s 25(1)(b) of the Act, noting other stressors in the respondent's life that are not work-related.

Grounds 1-3

These three grounds concern defences raised by the appellant at the hearing of reasonable action and reasonable administrative action relating to the employer, referred to by Mr Von Bibra, in requiring that the respondent not tuck his trousers into his socks. Mr Von Bibra's statement provided that earlier in 2016 the respondent had been asked repeatedly to cease tucking his trousers into his socks and it led to the respondent seeking union intervention in relation to an allegation of harassment of him by Mr Von Bibra and another employee.
The grounds of appeal place weight on the concluding words of the learned Commissioner's decision at [21] "Although the employer is successful with respect to grounds 2 and 3 …". It was argued that to be successful with respect to these grounds and the application of s 25(1A)(a) and (c), it was necessary for the Commissioner to have made findings that there be an illness of the mind or a disorder of the mind, and that illness or disorder must have arisen substantially from "reasonable action taken in a reasonable manner by an employer". It was submitted that [21] incorporated these findings, and that it followed from the determination that the defences succeeded, that the illness for which the worker made his claim arose substantially from his employment, ie that the employment contributed to the disease to a substantial degree within the meaning of s 3(2A). The learned Chief Commissioner erred in law when he said at [21] that although the employer succeeded on grounds 2 and 3, it failed on ground 1, and that the Tribunal could not be satisfied that a reasonably arguable case exists. It was submitted that an error of law was made because there is no requirement that all grounds of a reference must succeed, and there is nothing inconsistent in the finding that grounds 2 and 3 are made out, and ground 1 fails.
The respondent's arguments regarding these grounds were:
"23This ground of dispute could only meet the requirements of a reasonably arguable case, if the 'administrative action' relied upon was causative of the injury for which the Worker claimed compensation. This follows from the plain interpretation of section 25(1A), which only operates and applies if two preconditions are met:
a The existence of a disease or disorder of the mind; and
b That the disease or disorder arise substantially from reasonable administrative action.
24Section 25(1A) has no work to do in excusing liability for payment of compensation unless there is a liability for an injury pursuant to section 25(1)(b) of the Act and which injury is substantially caused by reasonable administrative action. The substantial contribution causation test to be met in each case is the same.
25Because the major contributing factor, even on the Employer's case, were the events involving Mr Dicker on 7 October 2016, the Chief Commissioner was correct to reject reasonable administrative action as a basis for finding a reasonably arguable case.
26The only evidence of 'administrative action' was contained in Mr Von Bibra's statement about the sock tucking issues. As events on 7 October 2016 involving Mr Dicker had nothing to do with actions taken by the Employer about sock tucking, they could not provide a basis for a reasonably arguable case pursuant to section 25(1A) of the Act."
These submissions provide a complete answer to the arguments advanced by the appellant. There was no suggestion on the evidence that the requirements given in relation to "sock tucking" had anything to do with the events of 7 October 2016. The evidence was that the "sock tucking" requirements had been earlier in the year. As a defence, it was tangential to the incident on 7 October 2016. There was no finding made by the Chief Commissioner of a causal connection between the respondent's incapacity for work resulting on 7 October 2016 and the "sock tucking" requirement. The submission that a finding of a causal connection is to be implied relied on part of one sentence in the learned Commissioner's decision at [21]: "Although the employer was successful with respect to grounds 2 and 3 …", taken out of context. The Commissioner's decision should not be read in that piecemeal fashion. A consideration of the entirety of the Commissioner's decision makes it clear that the finding said to have been made was not made at all. At [10] the learned Commissioner said:
"Grounds two and three can be disposed of quickly. Counsel for the employer indicated that if the events outlined by Mr Von Bibra in his statement about the occasional troubled relationships since February 2016 and the dealings with the worker in respect to the worker tucking his trousers into his socks are causative of the claimed condition then the employer says it has acted reasonably in relation to those difficulties and its actions in that regard are administrative in nature. I was referred to paragraph 24 to 25 and 45 to 53 of Mr Von Bibra's statement. The worker did not make any submissions to the contrary. In my view it is clear that if those events are causative of the worker's condition then it is reasonably arguable that the statutory defences are available to the employer and therefore grounds two and three of the reference are made out."

It can be seen that the success of grounds 2 and 3, which the Chief Commissioner spoke about at [21], was conditional on such action being causative of the respondent's condition. At [20] the Chief Commissioner noted that: "The opinion of Dr Chow and that of the general practitioner, in her certificate, link the cause of the worker's condition to the event or events on 7 October 2016." And significantly, at [21] the Chief Commissioner stated: "As to the event or events the worker complains about on 7 October 2016 the employer has not adduced any evidence or plausible potential cause inconsistent with liability."
It is evident from the Chief Commissioner's reasons in their entirety that the appellant's argument lacks merit. The imputed finding of causation with respect to "sock tucking" is contrary to the actual findings expressly set out in the decision, and contrary to the reasons articulated by the Chief Commissioner.

Ground 4

Submissions for the appellant drew attention to the requirement in s 25(1)(b) of the Act that compensation is only payable for a disease if the employment contributed to the disease to a substantial degree. The submission was that there were plausible potential causes inconsistent with liability. The reference to "plausible potential causes" is to the judgment of Evans J in St Helens Oysters Pty Ltd v Coatsworth at [14], referred to in the reasons of the Chief Commissioner: see [12] above. It was pointed out that these causes were non work-related and they may have been causative of the respondent's "stress, anxiety and condition". It was submitted that the Chief Commissioner failed to consider and make findings as to the causative relevance of the following evidence:
aThe action of the employer in respect to the respondent tucking in his socks.
bThe suicide of the respondent's brother: referred to in Dr Chow's report and Mr Von Bibra's statement.
cThe respondent's mother's psychiatric condition requiring inpatient treatment at Spenser clinic on and off: referred to in Dr Chow's report.
dThe respondent's history of panic disorder: referred to in Dr Tamimi's report.
eThe birth of the respondent's child and the extent of his contact with the child and mother: referred to in Dr Chow's report and Mr Von Bibra's statement.
fThe reaction of the respondent (exhausted and annoyed) at the actions of the employer to its employees: referred to in Dr Tamimi's report dated 16 December 2016.
"He did not mention anything specific happening in February 2016 other than he was elected then to be a union representative and that put some extra responsibility on his shoulders to want to be the nest for his co-workers but he felt exhausted and annoyed as sometimes the employer is not happy or doing the right thing for his employees."
gThe visits to doctors a number of times before 7 October 2016 about his workplace difficulties: referred to in Dr Chow's report.
hThe report of Dr Al Tamimi and Dr Tamimi's medical certificate that stops short of expressing an opinion on what was the most significant causative factor of the worker's condition.
iThe report of Dr Chow which did deal with the issue of most significant causative factor but made clear that this was in the light of ignorance as to other causes.
It was the appellant's submission that Dr Chow's opinion as to the event on 7 October 2016 being the most significant factor in the development of his condition must be read as subject to the unknown impact of other stressors. It was submitted that to read it any other way would be an error of law. It was submitted that the employer had provided evidence of plausible and potential causes inconsistent with liability, as mentioned above. It was said to be reasonably arguable that following a contested hearing the claim may be rejected because it might not be shown at the hearing that the events of 7 October 2016 were the most significant factor in the development of the disease for which the claim is made.
I observe that not all the evidentiary material was "provided" by the appellant, some of the material came from the respondent's documents, but nothing turns on that. At a s 81A hearing, an employer may point to an absence of evidence or deficiencies in unchallenged material and rely upon that to show a reasonably arguable case exists concerning liability: St Helens Oysters Pty Ltd v Coatsworth at [12] and [14].
It was the respondent's submission on appeal that while the issue raised in the referral was whether the worker suffered a disease to which his employment contributed to a substantial degree, the respondent was not constrained to establish an entitlement pursuant to s 25(1)(b), and there were a number of pathways to liability that were open under the Act. The condition of the respondent may be found to be an injury for the purpose of s 25(1)(a), and if so, there were unchallenged events involving Mr Dicker in the work-place on 7 October 2016, and immediate incapacity. Further, that if the respondent had some pre-existing psychiatric condition or symptom, then it was open to conclude that the events on 7 October aggravated that condition. It was pointed out that the employer's own evidence and case, noting Dr Chow's report, was that Mr Dicker's abuse caused the psychological injury within the meaning of s 25. As for all the factors identified by the appellant, it was submitted that there was no evidence before the learned Chief Commissioner about the degree to which each of those may have contributed to the respondent's injury or disease. Furthermore, there is a complete absence of evidence that any one of those factors amounted to a substantial contributing factor. It was emphasised that the appellant bears the onus of proof with respect to a s 81A referral: Lamont v MRD Supermarkets Pty Ltd at [10], [16] and [17].
The appellant, in reply, contended that it did not make the concession in proceedings before the Chief Commissioner that the events on 7 October were causative. In fact, the appellant contended that the Chief Commissioner was wrong in stating that the appellant's counsel had conceded that the non-vocational factors could not be said to be causative (see the Chief Commissioner's reasons at [9] above). I have carefully read the transcript of proceedings before the Chief Commissioner, and the concession was made. The Commissioner asked counsel for the appellant about Dr Chow's report and the reference to non-related work factors, and counsel replied:
"Sorry, Sir let me be clear. I am not submitting to you and it is not the employer's case that there are non – that the causation ground I raised because there are absolutely non-vocational factors which the employer says are more causative. So relevant of that comment, or the relevance of Dr Chow's evidence in that regard goes to the submission that the Tribunal in my submission needs to be careful in accepting the history as limited as it is and is given by Mr Medwin in claim format which is repeated in the initial medical certificate to the extent that we are told in February 2016 things are a bit difficult – but the only thing that we have any remote – I am not even going to say 'particularly' – any remote explanation of is something that occurred on the 7^th October 2016 and my submission is that Mr Medwin's account or history that he gives, needs to be treated with caution which is demonstrated by the contribution that appears in Dr Al Tamimi's report in December and Dr Chow's observation that he knows that there are non-vocational issues from the medical records from Dr Al Tamimi that Mr Medwin didn't explore those issues with Dr Chow. My submission is not that there are non-vocational factors which of are importance than the vocational factor".
While the transcript is evidently an imperfect record, the effect of counsel's concession is clear. The matter is put beyond doubt when the Chief Commissioner restated the appellant's position for the benefit of the respondent who had not heard part of the proceedings:
"And the first one, for your benefit Mr Medwin, was – if you look at page 6 of Dr Chow's report, question (f) and the final two paragraphs of his answer to question (f), I asked Mr Taylor what I was to make of those comments and Mr Taylor indicated to me that he was not submitting that there were non-vocational factors that were causative of your condition but he was submitting that those comments go to the reliability of the history that you provided and which is demonstrated when you compare what – the history given to Dr Chow and the history provided by Dr Al Tamimi."
Counsel did not cavil with that restatement. That concession represents the appellant's position, not only for the purpose of the s 81A hearing, but also for the purpose of this appeal. This appeal is concerned with the correctness or otherwise of the Chief Commissioner's determination in light of the issues as defined by the parties, having regard to any concessions made at that hearing, and the evidentiary material before the Tribunal. For an unexceptional appeal such as this, the appellant is bound by its concession: Suttor v Gondowda Pty Ltd (1950) 81 CLR 418 at 438, and indeed, it has not been argued otherwise.
It is convenient to consider the appellant's argument in the context of the pathway of liability in s 25(1)(b), that is, that the injury suffered by the respondent is a disease, and the question is whether his employment contributed to a substantial degree within the meaning of s 3(2A). I note that by virtue of s 3(2A) of the Act, a worker's employment contributes to a disease to a substantial degree only if it is the major or most significant factor.
It was open to the learned Chief Commissioner to proceed on the basis of the undisputed opinion of Dr Chow that the event on 7 October was the "most significant factor" in the development of the condition. There was no countervailing opinion. While there were other stressors and Dr Chow acknowledged that he could not confidently comment on the impact of these non-work-related factors, he nonetheless concluded that the event on 7 October was the "most significant factor". This opinion was expressed without reservation, and it was advanced in knowledge of these other stressors. It was an opinion that stands to reason given the timeline of the worker functioning in the work place until the events of 7 October. There was no evidence at all that one of the other stressors was significant in the development of the condition. Dr Chow could not have reached his opinion that "the event of 7 October 2016 was the causative factor of the developed condition and the most significant factor in the development of the condition" if the appellant's argument as to the effect of his report is correct, and unless Dr Chow had discounted other factors as being the most significant.
Contrary to the argument of the appellant, the Chief Commissioner was not bound to treat Dr Chow's opinion as to the most significant cause of the respondent's incapacity, as open to doubt. The opinion was advanced by the appellant, the disputer to the claim, not undermined and conceded to be correct.
The potentiality of other stressors as being causative, and, more particularly, the most significant cause, has not been shown. It should be borne in mind that in the proceedings before the Chief Commissioner, the appellant had the onus of proof. According to the evidentiary material before the Chief Commissioner, and the stance taken by the appellant to the opinion of Dr Chow, it was entirely open to the Chief Commissioner to conclude that there was not a reasonable prospect of the claim being rejected following a final hearing. It was reasonably open to the Chief Commissioner to conclude that, in the words of Evans J in St Helen's Oysters at [14], there was no evidence of "plausible potential causes that are inconsistent with liability".
The appellant has not demonstrated that the Chief Commissioner made an error of law in concluding that the appellant had not discharged its onus of proof, and in concluding that a reasonably arguable case did not exist concerning the respondent's claim. The appeal will be dismissed.