[co-author: Danielle Webb]
The recent judgment of the New South Wales Court of Appeal in Paul v Cooke  NSWCA 311 held that the scope of a negligent defendant’s liability does not extend beyond the occurrence of a particular risk that cannot be avoided with the exercise of reasonable care and skill.
In 2003, Ms Paul had a scan to determine whether she had an intracranial aneurysm. Dr Cooke, a radiologist, failed to diagnose the aneurysm and thereby breached his duty of care to her. The aneurysm was eventually diagnosed in 2006. Ms Paul underwent endovascular surgery to remove it. Unfortunately, the aneurysm ruptured during the surgery (without any lack of skill or care on the part of the surgeons). Ms Paul suffered significant injuries.
Ms Paul claimed her injuries were caused by Dr Cooke’s negligent failure to diagnose the aneurysm in 2003.
The Court of Appeal held that it was highly likely that, had the surgery been performed in 2003, Ms Paul would have suffered no harm. This was because there was a 1 percent chance of the aneurysm rupturing during surgery. However, this did not mean that Dr Cooke’s negligence caused the injuries Ms Paul suffered in 2006. This was because the delayed diagnosis did increase the risks associated with surgery (the aneurysm did not change in size, shape or propensity to rupture during those the years). As a result, while Ms Paul suffered injuries during surgery in 2006 which she probably would not have suffered if she had had surgery in 2003, Dr Cooke’s failure to diagnose the aneurysm did not cause the aneurysm to rupture.
The Court noted that, when determining whether Dr Cooke’s liability should extend to the injuries Ms Paul sustained, policy considerations (social, moral and economic) were relevant. These considerations are highly fact-specific and depend on the circumstances of each case. The Court held that the risk that eventuated (ruptured aneurysm) was relevantly unconnected with Dr Cooke’s breach of duty and Ms Paul had not identified any social, moral or economic principle or policy which favoured an imposition of liability on Dr Cooke in the circumstances.