Pre-existing condition and the shifting evidentiary onus

Motor Vehicle Directions

Glen v Sullivan [2015] NSWCA191

Date of Judgment: 9 July 2015

NSW Court of Appeal: Sackville AJA with Beazley P and Ward JA agreeing


Ms Glen was involved in a motor accident on 10 October 2009 and her claim proceeded to trial before Letherbarrow SC DCJ in the District Court at Sydney. Surveillance evidence adverse to the claimant was relied upon by the insurer. His Honour made relevant findings:

  • The claimant’s credit was such that her evidence, especially as to the extent of her injuries and disabilities, could not be accepted unless the evidence was corroborated
  • The claimant had a long-term significant psychiatric history involving, inter alia, self-harm and long bouts of recurrent and very serious depression for which she took medication continuously
  • The accident was frightening and left the claimant in considerable shock and caused injury to her left ankle. She had developed a complex regional pain syndrome in her left hand and wrist as a result of the accident which caused her psychiatric condition to destabilise
  • By October 2010, the claimant was significantly misrepresenting the level of her symptoms to most of the treating doctors, and continued to do so thereafter
  • By October 2011, the claimant was no longer suffering from complex regional pain syndrome or any other physical condition that would render her unfit for her pre-accident employment or otherwise affect her pre-accident earning capacity
  • Any aggravation of the claimant’s pre-accident psychiatric condition had ceased by October 2011. The psychiatric problems from which she had suffered after that date were a consequence of, and caused by, her pre-existing condition.

The plaintiff appealed, submitting that the trial judge had failed to disentangle the non-compensable causes of the claimant’s continuing psychiatric disabilities from the compensable causes. Further, once it was accepted that there was a causal connection between the accident and the claimant’s subsequent psychiatric disabilities, at least for some time, it was the insurer who was required to exclude the accident as a contributing cause of her post-accident condition. The plaintiff submitted that the trial judge was in error by simply applying section 5D of the Civil Liability Act 2002 [NSW] and had overlooked the principles established by cases such as Watts v Rake (1960) 108 CLR 158. The plaintiff submitted that the insurer had failed to adduce evidence satisfying the requirements of Watts v Rake, and further, that the evidence relied upon by the insurer was equivocal and left the relationship between the accident and the claimant’s psychiatric condition uncertain.

Decision reasons

Sackville AJA reviewed the reasoning in Watts v Rake in detail and the subsequent High Court commentary upon that decision in Purkess v Crittenden (1960) 114 CLR 164.

Sackville AJA noted that there was no dispute at the trial or on appeal that the accident had caused the claimant to sustain some physical and psychiatric injuries and that she had continued to suffer from serious psychological disabilities as at the date of trial. Therefore, in accordance with Purkess v Crittenden, as the claimant had made out a prima facie case that her continuing psychiatric disabilities resulted from the motor accident, the onus of adducing evidence showing that her disabilities were wholly the consequence of the claimant’s pre-existing condition fell on the insurer.

Further, the insurer bore the onus of adducing evidence that the claimant’s psychiatric disabilities attributed to the accident had resolved before the date of trial.

Sackville AJA emphasised that the onus on the insurer was not one which required it to prove, on the balance of probabilities, that the claimant’s continuing disabilities were not causally related to the accident. Once the insurer had adduced evidence (that the claimant’s psychiatric disabilities attributed to the accident  had resolved before the date of trial); the burden of proof on the balance of probabilities remained with the claimant.

The combination of the surveillance material and the qualified medical opinions obtained by the insurer were held to support the insurer’s case on causation. Sackville AJA found that the insurer had discharged its onus of adducing evidence probative of the fact that any causal relationship between the accident and the claimant’s psychiatric disabilities had ceased well before the trial.

As the claimant’s credit had been impugned, and the views expressed by her treating and qualified doctors rejected, the claimant therefore failed to satisfy her the evidentiary onus.


The decision sends a strong message both to claimants and insurers regarding who bears the evidentiary onus in certain circumstances, and how that may shift during the trial.

In situations of a pre-existing condition aggravated by a compensable injury, it is incumbent upon the insurer to provide evidence to establish that any aggravation caused by the accident has ceased, or which at the least quantifies, the extent to which the pre-existing condition remains a cause of incapacity. The decision emphasises that once such evidence is adduced, then the claimant bears the evidentiary onus to satisfy the tribunal of fact of a causal connection on the balance of probabilities.

The decision emphasises that the insurer’s evidence must be more than equivocal in relation to the relevant issue. Evidence which merely raises doubt may not satisfy the test, noting the comments by Sackville AJA that the evidence must be affirmative of the proposition being put forward by the insurer.

Authored by Charles Williams, Partner, Sydney.

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