Paul v Cooke – timing difference not enough to prove causation
The High Court recently dismissed the special leave application brought in this case by Ms Paul, seeking to overturn the New South Wales Court of Appeal’s decision rejecting her claim.
As may be known, the case concerned a delay in diagnosis of an intracranial aneurysm suffered by Ms Paul. She underwent a head CT Scan in 2003 and Dr Cooke, the radiologist, negligently failed to identify and therefore diagnose the aneurysm. In 2006, following a further scan, the aneurysm was diagnosed. Sadly during surgery to remove the aneurysm it ruptured causing Ms Paul a stroke and serious injury.
For the purposes of the special leave application it was accepted that the risk of rupture/stroke associated with the operation Ms Paul underwent in 2006 was no different to the risk had she undergone surgery in 2003, as would have occurred had Dr Cooke not negligently failed to diagnose the aneurysm.
The New South Wales Court of Appeal had concluded that Dr Cooke’s negligence was not the cause of Ms Paul’s surgical complication. His negligence changed the timing of surgery but did not alter the risk associated with it. It did not matter that it could be fairly said that had Ms Paul undergone surgery in 2003, it was very unlikely that she would have suffered the rupture and stroke she did in 2006. Dr Cooke had breached his duty of care, but was not responsible for the stroke.
The High Court rejected the application for permission to appeal from such decision (the special leave application), because its members, in essence, agreed with the Court of Appeal. There was not sufficient doubt to warrant granting permission to appeal.
There is now a clear distinction between diagnosis and treatment cases on one hand and failure to warn cases on the other in this important context. In the latter, it is well recognised (and recently reaffirmed by the High Court in Wallace v Kam,  HCA, 19) that a patient can succeed in a claim if able to show that had they been properly warned of the risks associated with treatment they would have delayed proceeding, even if ultimately such surgery or treatment was likely to occur and would involve the same risks as eventuated at the time of their operation. More must be shown in diagnosis/treatment cases. A negligently caused delay in surgery carrying the same risk is not sufficient for liability.
Paul v Cooke failed, apart from on general causation principle, by reason of the terms of section 5I of the NSW Civil Liability Act which provides that:
“a person is not liable in negligence for harm suffered by another person as a result of the materialization of an inherent risk.”
The New South Wales Court of Appeal rejected argument on Ms Paul’s behalf that this section was limited to materialisation of a risk associated with treatment provided by the negligent defendant. This section was interpreted as broad enough to exclude liability when the inherent risk that materialised, as occurred in the surgery performed by the team caring for Ms Paul in 2006, well after the negligent failure to diagnose by Dr Cooke. Interestingly the WA equivalent provision, section 5P is differently worded from the New South Wales legislation and does seem to be limited to inherent risk associated with the defendant’s treatment.