In the case of Vanoostwaard v AAI Limited t/as GIO [2023] NSWPIC 97 Member Cassidy has confirmed an earlier decision that in a ‘wholly or mostly at fault’ dispute involving a single vehicle only, ‘fault’ should be given its usual meaning of ‘responsibility for the accident’ rather than the meaning of fault as defined in s1.4 of the Motor Accident Injuries Act 2017 to mean ‘negligence or any other tort.’

Key Takeaways

This case has confirmed Member Cassidy’s approach to the definition of ‘fault’ in a single vehicle accident in a ‘wholly or mostly at fault’ dispute.

Insurers should note that, on Member Cassidy’s approach, in a single vehicle accident without evidence of another person or thing being responsible for the accident, the claimant will be responsible and therefore wholly at fault. However, it must also be acknowledged that other Members continue to approach this question differently.


On 14 October 2022 Mr Vanoostwaard was seriously injured after his motorbike collided with a bank of dirt after crossing a cattle grid on the Thunderbolts Way. There were no other vehicles involved and there was no external cause nominated by the claimant as having caused the accident; he essentially alleged that he lost control of the motorbike while riding over a cattle grid.

The insurer accepted liability for statutory benefits for the first 26 weeks but denied benefits beyond 26 weeks on the basis that the claimant was wholly or mostly at fault as defined under s3.11 and 3.28 of Motor Accident Injuries Act 2017 (MAIA). The claimant commenced an application in the Personal Injury Commission to determine this ‘wholly or mostly at fault’ dispute.  


The application was heard by Member Cassidy who considered the following:

  • No other motor vehicle was involved.
  • The claimant’s motorbike was not faulty.
  • The road and cattle grid were not poorly designed, installed, or maintained.
  • There were no hazards on the road surface.
  • The claimant had successfully crossed other cattle grids to the accident.
  • Others travelling with the claimant had crossed the subject cattle grid without issue.

Having considered the circumstances and the evidence, Member Cassidy determined that the accident occurred when the claimant lost control of his motorbike because his front tyre hit the cattle grid and his bike jolted, he shifted in his seat and, when regaining his seat, he accidentally adjusted the throttle and accelerated to an embankment and was unable to stop before colliding with it.

Member Cassidy considered the meaning of fault in the context of this single vehicle accident and the wholly or mostly at fault dispute that she was required to determine. She noted that the definition of fault is set out in s1.4 MAIA as being ‘negligence or any other tort’. However, it was Member Cassidy’s view that this definition of fault does not apply in connection to the meaning of fault in ss3.11 and 3.28. This was because the law of torts and the principles of the tort of negligence do not apply to the scheme of statutory entitlements under the MAIA and because the claimant would have no cause of action against himself and cannot sue himself for damages.

It was therefore Member Cassidy’s view that the word fault in ss3.11(1) and 3.28(1) should be given its ordinary or usual meaning, which is ‘responsibility for the accident.’ This confirmed an earlier decision of Member Cassidy in Yankovich v AAI Limited t/as GIO [2022] NSWPIC 137.

Member Cassidy referred to her usual approach in single vehicle crashes to determine whether a claimant is wholly at fault, being to enquire as to whether anyone else or anything else was responsible for causing the accident. If there was someone or something else responsible, then the claimant would not be wholly at fault. In the present case, there was nothing other than the way in which the claimant rode his motorbike that caused the accident and therefore he was responsible for the accident.


Although the burden of proof is on the insurer to establish that a claimant is wholly or mostly at fault, in a single vehicle accident where there is no external cause – i.e. no other person or thing – that has been identified as contributing to or causing the accident, the absence of other causes would be sufficient to satisfy Member Cassidy’s line of reasoning to find the claimant responsible for the accident and therefore wholly at fault.

Although not expressed by the Member in these terms, this is somewhat akin to the principle of res ipsa loquitor – the fact of the accident itself, absent any other explanation, is sufficient to imply negligence, or ‘fault’ in the context of statutory benefits as the case may be.

It is important to bear in mind that other Members continue to approach this question differently, and this decision is not binding on them.

Further information / assistance regarding the issues raised in this article is available from the authors, Erin Woodward, Special Counsel, Freya Taylor, Lawyer, or your usual contact at Moray & Agnew.