Powney v Kerang & District Health  VSCA 221 saw the Victorian Court of Appeal address an appeal from a jury trial. However the focus of the Court was not only on the role of the jury, extending to evidentiary gaps in medical negligence cases and to increased risk causation cases.
The patient had argued that an intramuscular injection of pethidine was injected into this left arm by a nurse in a negligent manner, in that the needle was uncapped and not sterile. The hospital accepted that an intramuscular injection given to the patient by its staff in the course of his stay (during which there were five injections) was the source of the infection he later developed. However, it argued that the injection was not given negligently, but in accordance with accepted practice. In any event, the hospital contended that any alleged departures from reasonable practice were not a cause of the infection: . The jury found for the hospital and judgment was entered in its favour.
Direction to the jury about causation
The trial judge had ruled that the jury was confined to determining factual causation and, contrary to the submissions made by the patient’s counsel, not to the consideration of the matters set out section 51(2) of the Wrongs Act 1958 (Vic).
Section 51 deals with causation; subsection 1 dealing with the usual factual causation proof. Subsection 2 permits a court to hold a defendant liable for the harm sustained by the plaintiff absent proof of factual causation, provided the court is satisfied that the responsibility for the harm should be imposed on the negligent party. (The equivalent section in New South Wales is section 5D(2), Civil Liability Act 2002 (NSW)).
Judge, not jury, to address scope of liability issues
The Court held at  that the court (namely, the trial judge) must make a normative judgment of the circumstances surrounding the infliction of the harm, taking into account precedent and policy as required by section 51(4) explain that judgment. Subsection 4 provides that for the purpose of determining the scope of liability, the court is to consider (amongst other relevant things) whether or not and why responsibility for the harm should be imposed on the negligent party. Only judicial scrutiny can resolve whether or not and why responsibility for the harm should be imposed on the negligent party in accordance with established principles: 
At , the trial judge was therefore correct to reject the submission that the jury should determine in an appropriate case, in accordance with established principles, whether negligence that cannot be established as a necessary condition of the occurrence of harm should be taken to establish factual causation: section 51(2).
Evidentiary gap cases
At  ff, the Court of Appeal went on to discuss section 51(2) generally and when it might properly be applied. It is worthwhile setting out the full text of the Court’s comments at  – :
… the section was not intended as a fall back provision in a conventional case for a plaintiff who is unable to establish factual causation. Rather, it was designed to accommodate cases quite out of the ordinary — particularly those involving exposures to a particular agent on multiple occasions, all of which contributed to a disease process but factual causation could not be attributed to a specific exposure. Alternatively, it was to be employed where scientific evidence may be developing in identifying the level of exposure to a particular agent necessary to produce injury.
 Notwithstanding the Victorian legislature’s adoption of the word ‘appropriate’ as opposed to ‘exceptional’, those parts of the Ipp Report, the Second Reading Speech and the Explanatory Memorandum to which we have referred demonstrate that Parliament did not intend that the circumstances in which this provision could be engaged would extend to a simple case (such as this) where a plaintiff could not make out his or her case on factual causation
 The appellant’s submissions appear to treat expert evidence suggesting reasonable precautions which may reduce the risk of injury … as being sufficient to invoke the use of the section. However … that could not be enough to trigger operation of the section. This was simply a failure to prove what was in truth a very weak case; the appellant was unable to prove his case beyond demonstrating a somewhat increased risk of injury arising out of a contentious single event. It was not suggested that there was some body of developing scientific knowledge on this issue. Section 51(2) was not directed to the appellant’s situation.
In concluding remarks at , the Court was not willing to make obiter comment on the types of cases which may fall within section 51(2) – though to some extent that is done at .
Increased risk and causation
At  the Court commented that in Australia increased risk of injury alone resulting from a tortious act or omission is insufficient to make out a case on causation. However at , an increase in the relevant risk of injury, particularly if significant, is a relevant consideration for a tribunal of fact as one of the matters to be taken into account in determining if factual causation is made out.