Michelle Vegter, explains the New South Wales Court of Appeal in the recent decision of Gett v Tabet

Background  

When a 6 year old girl presented at the hospital suffering headaches, nausea and vomiting, the treating doctor considered her to be affected by chicken pox. It was not until she suffered a seizure that a CT and EEG were performed and it was discovered that, in fact, she had a brain tumour which had been growing for some time. The tumour was removed, and the child was left with significant brain damage as a result of both the seizure and the operation.  

The alleged negligence arose due to the CT scan having been performed on 14th January 1991 rather than on 13th January 1991 prior to the seizure. Relevant to this was that the child had some indicators of brain trauma prior to the seizure, and that the seizure caused around 25% of the brain damage. The remainder of the brain damage was the result of an operation to remove the tumour. As a result of the failure to perform the CT scan the plaintiff alleged she had lost the chance of avoiding the seizure and thereby sustaining less brain damage.  

First instance Decision and Appeal  

At first instance, the New South Wales Supreme Court found that the failure to perform a CT scan on 13th January resulted in the plaintiff losing the chance of a better outcome. The Court cited the authority of Rufo v Hoskings which established the principle of loss of chance in circumstances of medical negligence.  

The decision was however overturned on appeal and the Supreme Court’s reliance on Rufo heavily criticised. Particularly, the Court of Appeal condemned Rufo for stepping outside its allowable jurisdictional limits by attempting to impinge upon the exclusive authority of the High Court to expand the law of tort to such an extent. The Court went so far as to say that Rufo “involved a departure from conventional principles and... is plainly wrong”.

Implications  

The Court of Appeal has made a definitive statement regarding the exclusive authority of the High Court to determine whether or not the law of tort should be expanded in order to encompass such aims for loss of chance.  

Any other court which attempts to redefine the boundaries of causation would be operating outside its jurisdiction and, as in this case, run the risk of its decision being overturned on appeal.  

Importantly, the decision also highlights the desirability of preserving the present limits of tort law.  

The decision emphasises the difficulty in awarding damages for a loss of chance, due not only to the virtual impossibility of quantification but also to the subversion of the causation principle in such cases; traditionally the prerequisite for a sustainable negligence claim. The reluctance to expand tortious limits into an area with virtually undefinable outer boundaries is encouraging in that it reaffirms causation as the crucial element of actions in tort.  

The Court of Appeal’s denial of the loss of chance argument prevents inevitable subversion of the correct application of the onus of proof. The word ‘chance’ by definition would not allow the onus of proof to be satisfied on the balance of probabilities, considering that the latter concept is generally accepted in common law to mean ‘more probable than not’. With credence to that definition, any attempt to satisfy the onus of proof upon a mere speculation as to the outcome of some action or omission is clearly unsustainable.  

A successful loss of chance claim would directly contradict the civil liability legislation of every Australian state and territory, considering that the primary principle of such is that a causal nexus between the defendant’s conduct and the plaintiff’s injury must be established on the balance of probabilities in order to give rise to liability for negligent conduct.