Vines, Prue --- "Editorial: Asking who, not what" [2023] PrecedentAULA 12; (2023) 175 Precedent 2

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ASKING WHO, NOT WHAT

By Prue Vines

The legal enquiry into causation is different from that of science and philosophy. A major difference of law is that we ask ‘who’ rather than ‘what’ because we are determining liability. But as medical and other technology increases, and we better understand how illnesses such as dust diseases develop, causation becomes harder to prove. In this edition, we consider some issues raised by genetic, epidemiological and statistical evidence.

It isn’t only new matters that complicate causation – multiple possible causes, for example, have always challenged us. The standard test for causation in law is the ‘but for’ test, which has often been supposed to exist separately from the ‘material contribution’ test. Neil Foster, however, argues strongly that material contribution should be seen as part of the ‘but for’ test. In his view, Bonnington Castings v Wardlaw^[1] shows that a material contribution need not be the only cause, and therefore can be seen as part of rather than an exception to the ‘but for’ test. Dominic Villa SC gives us a brief outline of how the civil liability acts have altered the landscape of causation, maintaining the ‘but for’ test and creating two approaches to ‘exceptional cases’ across Australia.

Richard O’Keefe notes that the onus of proof of causation in medical negligence is not necessarily very demanding, merely requiring an inducement ‘in the mind of the fact-finder, an actual persuasion that the fact [did] exist’. How to create that inducement? The easiest way is for all the experts to agree that there is a causal connection, but expert evidence is not the only way to establish causation. It has been argued that causation can be established by proof of breach alongside an injury that it is known can be caused by such a breach. This is controversial, as is the view that a significant increase in risk can be sufficient for causation.

Causation in medical negligence becomes even more complicated when new medical techniques arrive. Drs Ken Maclean and Sara Golru both discuss genetic or genomic evidence. One problem Golru addresses is that genetic evidence may show an inherited tendency to react to a toxin, where the gene increases risk only when there is exposure – or it may be that the gene may increase risk regardless of exposure. It is not always possible to determine which of these categories the testee falls into. If genetic testing does not indicate an illness but merely shows a tendency, the testing may lead to mental distress, and disclosure of the results may lead, for example, to discrimination or loss of insurance. Untangling causation with genomic testing where multifactorial diseases are at issue can be difficult because genetics may not be the only causal factor, as Maclean notes. This is a new area in which extra knowledge seems to throw up further complexities. Martin Rogalski notes that latent onset diseases – for example, silicosis and mesothelioma – and new chemicals like polyfluoroalkyl are becoming understood faster and pose many causal issues.

How legal causation meshes with morality is the subject of Bridie and Adrian Walsh’s fascinating article. They consider the extent to which moral luck is involved in cases where factual causation is established but scope of liability is not, or where there is a very wrongful breach but it does not lead to a bad outcome and therefore there is no liability. Their concern is that this does not match our moral sense, which focuses on the wrongfulness of the breach. This may be true, but it is also true that psychologically we do appear to blame people whose wrongdoing leads to a bad outcome far more than those who merely do wrong.^[2] Ultimately this is why proof of negligence requires proof of the causation of injury as an essential element of the cause of action.

Prue Vines is Professor of Private Law at the University of New South Wales. She specialises in torts and apologies in civil liability as well as unexpected consequences of tortious litigation. Among many books and articles, she is co-editor and co-author of Fleming’s Law of Torts, 10e and 11e.

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^[1] [1956] UKHL 1; [1956] AC 613.

^[2] JK Robbennolt, ‘Outcome severity and judgments of “responsibility”: A meta-analytic review’, Journal of Applied Psychology, Vol. 30, No. 12, 2000, 2575–2609.