Adverse credit and weight of evidence in personal injury matters

The weight given to evidence often depends on the credibility and reliability of its source. Where evidence fails to be credible at face value, practitioners are expected to provide supplementary material that builds credibility. Evidence that relies on non-credible, untested or unreliable information risks being excluded, discounted or given diminished weight.

The importance of relying on credible evidence and corroborating supplementary material was highlighted in CLA v BUU [2026], a recent decision in the Personal Injury Commission.

The findings by the Member on first instance and the President on appeal provide practical guidance on addressing adverse credit findings, corroborative evidence and medical opinions based on a claimant’s self-reported history.

Background

The appellant alleged he sustained a psychological injury while serving as a police officer. The appellant claimed he was exposed to a number of ‘stressful, harrowing situations’ including a stabbing and a traumatic motor vehicle accident.

The appellant was involved in a serious incident on 22 January 2023, in which he and a colleague applied excessive force to a vulnerable individual during a welfare check. After the incident, he was suspended without pay and was informed his conduct justified dismissal and the institution of criminal proceedings. The appellant resigned from his position at NSW Police in August 2023. 

The appellant made a claim for workers compensation benefits on 17 March 2023; the same day he was notified of his unpaid suspension. The claim was declined by the respondent’s insurer, and the matter was subsequently contested by the appellant in the Commission.

The parties’ competing positions

The Member was presented with two competing narratives on causation. The appellant submitted that he sustained a psychological injury, specifically post-traumatic stress disorder, after exposure to several traumatic events throughout the course of his employment, including a stabbing and motor vehicle accident. The appellant reported the incident on 22 January 2023, and any subsequent disciplinary and legal action was not ‘in any way’ causative of his injury.

The appellant relied on statements from his father and ex-wife, which he argued confirmed he suffered psychological symptoms after commencing his employment at the Insured and before the serious incident on 22 January 2023. The appellant also argued that his conduct and ‘poor judgement’ during the January 2023 incident were a result of an ‘undiagnosed mental illness’, which he believed indicated he was not ‘mentally well’ at the time of the incident.

The respondent submitted the appellant was psychologically well enough to work until 17 March 2023; when he was suspended without pay and charged with criminal offences. The respondent applied a ‘commonsense approach’ and submitted that the January 2023 incident and subsequent disciplinary and legal action had informed the appellant’s decision to claim workers compensation. The respondent submitted that the Insured’s disciplinary action was reasonable as the appellant was treated with procedural fairness and his mental health was monitored throughout the disciplinary process. The respondent also noted the appellant had failed to disclose any mental health conditions prior to 17 March 2023.

The Member accepted the appellant had been exposed to traumatic incidents over the course of his employment but noted he did not require psychological treatment or time off work until the date he was suspended without pay.

The Member’s assessment of credibility

In making his decision, the Member referred to Nguyen v Cosmopolitan Homes and noted the appellant had to satisfy the “onus of proof that the traumatic incidents were causative of a psychological injury” and the Member had to feel actual persuasion. The Member considered the acceptance of the appellant’s statement and oral evidence as “crucial” if he was to be persuaded that the appellant’s claim had satisfied this “onus of proof”.

The Member considered the appellant’s oral evidence to be “evasive, vague, confusing and self-serving”. On this basis, the Member was not persuaded by the statement or oral evidence of the appellant and considered it untruthful, “misleading, and unhelpful”. Based on this finding, the Member noted he would only accept the appellant’s evidence if it was ‘independently corroborated’. The Member found the evidence provided by the appellant’s ex-wife and father was not specific enough to corroborate his claims regarding causation.

Medical evidence and the fair climate doctrine

The Member considered whether the medical evidence submitted by the appellant was ‘given in a fair climate’ applying the findings of Snell DP in ACW v ACX. Due to the unreliability of the appellant’s oral evidence and the heavy reliance on a self-reported history of injury and symptomatology in his medical evidence, the Member found this medical evidence was not given in a fair climate. The Member was also of the opinion the assessing doctor failed to sufficiently consider the circumstances in which the appellant “first sought treatment for mental illness”. The Member preferred the medical evidence submitted by the respondent as the assessing doctor was given all the necessary information to form her opinion.

The Member gave significant weight to the respondent’s medical evidence and concluded the appellant had failed to satisfy the onus of proof for establishing a psychological injury and ruled in favour of the respondent.

Findings on appeal

The appellant appealed the decision on the basis that the Member erred in fact and law regarding the finding that the appellant was not injured in the course of his employment and submitted the Member failed to properly give weight to medical evidence and failed to give sufficient weight to the appellant’s ‘fear of disclosure and stigma’.

Why the appeal was dismissed

Notably, the appellant did not appeal the adverse credit findings made by the Member during the initial proceedings. The President noted the Member had ‘an advantage’ when considering the reliability of the appellant’s testimony as he had ‘heard and watched the lengthy cross-examination of the appellant’. The President noted the appellant’s failure to challenge the adverse credit finding and said this adverse credit finding would have a ‘concomitant effect’ on the weight and value of the appellant’s evidence. The President fully endorsed the Member’s adverse credit finding and considered the Appellant’s evidence ‘deliberately evasive [and] in parts untruthful’.

The President confirmed the Member’s approach to the testimony of the appellant’s father and ex-wife, noting the Member was ‘not assisted by what they had to say’ for the purposes of establishing causation. The President also confirmed the Member’s finding that the adverse credit findings against the appellant meant that the medical evidence that heavily relied on his self-reported history, including the reports of two medical assessors, was not given in a ‘fair climate’. The President also preferred the medical assessment served by the Insured. The President dismissed all grounds of appeal.

Key takeaways – credit and weight of evidence

This decision highlights the importance of credit findings in decisions and how these are dealt with on appeal.

• The adverse credit finding regarding the appellant’s evidence had an effect on all of the other evidence and anything, including the findings of the medical assessors, that relied strongly on the unverified testimony of the appellant was considered less favourably.

• The decision not to challenge the adverse credit finding on appeal meant the appellant was unlikely to successfully challenge the Member’s finding regarding liability as every ground of appeal was, to varying degrees, contingent on evidence the Member had already found unreliable.

• The decision also demonstrates the fair climate doctrine, as established in ACW v ACX, in practice. Medical opinions that rely too heavily on evidence provided by an unreliable or untrustworthy historian can be discounted or given less weight than medical opinion that did not.

Authors: Kate Ralph & Austin Steel

This publication is intended as a source of information only. No reader should act on any matter without first obtaining professional advice.