Martin v Minister for Health  WADC 15 was a claim arising from a right arm central catheter insertion (PICC), in which the claimant alleged he had suffered compression of his right medial nerve.
The defendant owed a duty of care to avoid causing him foreseeable harm that encompassed, in the factual circumstances of this case, the duty to perform early investigations following observable symptoms of nerve damage subsequent to the failed PICC line procedure: see .
Much of the judgment consists of a recitation of the evidence, but at  onwards Bowden DCJ discusses the Western Australian peer opinion provision (section 5PB) and notes that it has a provision such that the claimant bears the onus of proving that the defendant’s act or omission was negligent and was not an act widely accepted by his peers as competent professional practice or, if it was, the act or omission was, in the circumstances, so unreasonable that no reasonable health professional in the defendant’s position could have so acted or omitted to do the act complained of: see .
Breach of duty was found and ‘but for’ causation discussed (section 5C) with a finding in favour of the claimant (at ). There followed a discussion at  onwards of an alternate causation pathway based on material contribution:
303 The CLA provides that negligent conduct materially contributing to the plaintiff’s harm but which cannot be shown to have been a necessary condition of its occurrence may, in accordance with established principles, be accepted as establishing factual causation subject to considerations under s 5C(2)(a) and s 5C(2)(b).
304 The effect of these provisions is that, in appropriate cases, if fault cannot be established as a necessary condition of the occurrence of harm, actual causation may nonetheless be established. This question is to be determined on ‘established principles’. The court must consider whether and why responsibility for the harm should or should not be imposed on the tortfeasor and whether and why the harm should be left to lie where it fell.
305 Thus, where there is an ‘evidentiary gap’ which precludes a finding of factual causation on a ‘but for’ analysis, there are cases where, firstly, the contribution of each factor to the cumulative operation of factors in the occurrence of the total harm is unascertainable and, secondly, where the negligent conduct materially increases the risk of harm in circumstances where the state of scientific or medical knowledge makes it impossible to prove the cause of the plaintiff’s harm. In these cases s 5C(2) permits the finding of causation in an ‘appropriate case’ notwithstanding that the defendant’s negligence cannot be established as a necessary condition of the occurrence of the harm: Woolworths Ltd  – .
306 There is no reason why the defendant, who assumed the responsibility for providing care, should not have responsibility for harm caused to Mr Martin imposed upon them and there is every reason why the harm should not be left to lie with Mr Martin who resorted to a hospital for medical treatment, one aspect of which was negligent. The harm should not be left to lie with him.
307 If I am wrong in concluding that Professor Myers’ evidence established that Mr Martin would not have suffered a permanent disability if surgery was performed by 6 or 7 December 2012, the weight of the medical opinion is that Mr Martin would have been better off with early surgery but one cannot say the extent or degree to which he would have been better off. Professor Myers said Mr Martin would have ‘benefited from the surgery’ and had a ‘better result’. Dr Allison said he believed Mr Martin would have been ‘significantly better’. Dr Gillett agreed with Dr Allison that there was absolutely no doubt that treatment earlier would have achieved a better result and that a prompt decompression of the nerve may have seen Mr Martin return to full function. Similarly, the doctors agreed that the longer the period of compression the more likely there is to be a ‘worse’ result.
308 If failure to intervene cannot be shown to have been a necessary condition of Mr Martin’s harm, I would be satisfied on the balance of probabilities that it materially contributed to Mr Martin’s harm in accordance with established principles. That failure to intervene was one factor in the cumulative operation of factors in the occurrence of the total harm. It was part of a set of conditions necessary to the occurrence of that harm: Woolworths .
309 Either way I find causation under the CLA established.
With thanks to Karina Hafford for noting this decision.