When considering whether a negligence action will be won or resisted, it is important to think in terms not just of whether the supposed negligence caused particular harm in fact, but also whether a Court should find it appropriate that a negligent person be imposed with responsibility to pay damages for the harm. The evaluative assessments for which sub-sections 5D(1)(b) and 5D(4) provide must be undertaken before there can be a determination of a negligent person’s liability.
Those subsections provide as follows:
5D General principles
(1) A determination that negligence caused particular harm comprises the following elements:
(a) that the negligence was a necessary condition of the occurrence of the harm (factual causation), and
(b) that it is appropriate for the scope of the negligent person’s liability to extend to the harm so caused (scope of liability).
…
(4) 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.
Section 5D of the Act, whether or not it represents a development of the position at common law, imposes a two-limbed inquiry to be undertaken before a breach of duty may be found to give rise to liability. Sub-section 5D(1)(a) requires that the breach of duty be a necessary condition of the occurrence of the harm. That is the “but for” test of factual causation. Sub-section 5D(1)(b) requires the inquiry then to consider whether it is “appropriate” for the negligent person’s liability to extend to the harm found to have been caused by the application of the “but for” test.
This “scope of liability” test stands in the way of regarding determination of causation as a purely factual exercise. It has been described as reflecting McHugh J’s “scope of the risk” test from March v E & MH Stramare Pty Ltd (1991) 171 CLR 506 at 535, a test that asks whether the consequence of the negligent person’s conduct is fairly to be regarded as within the risk created by the negligence.
Scholars say the “scope of liability” test is evaluative. The High Court has said it is “entirely normative”: Wallace v Kam (2013) 250 CLR 375 at 383 [14]. Those abstract descriptions are of little practical help when the plaintiff in a novel case is planning the necessary submission that the negligent person should be imposed with responsibility for the plaintiff’s harm in accordance with section 5D(4) because it is “appropriate” for the scope of liability of the negligent person to extend to that harm.
The following guidance emerges from the cases.
First, it is clear that the two limbs are separate and distinct; a finding that the first limb has been satisfied may not be used to “pre-empt” a finding in relation to the second: Paul v Cooke (2013) 85 NSWLR 167 at 191 [104] per Leeming JA. But the facts that are relied upon to satisfy the first limb are far from irrelevant to the second inquiry. As Leeming JA said at 192 [110]:
It would be most surprising if scope of liability, which is central to establishing the limits of negligence, was confined to purely normative considerations. True it is that there are statements that the determination of factual causation is entirely factual and the determination of scope of liability is entirely normative, notably in Wallace v Kam … There is to my mind no basis in the statute or any decision on it to support the notion that the strength of the causal connection (or any other factual matter relevant to factual causation) is irrelevant to the determination of what is “appropriate”.
Secondly, a submission on why the second limb is satisfied should, as section 5D (4) indicates, explain why scope of liability extends in the case in question to the suffered harm. McHugh J’s “scope of the risk” test suggests this should be addressed by identifying the risk created by the negligence and showing why the consequence of the negligent person’s conduct is fairly to be regarded as “within” that risk. The proven facts must enable a submission that the community would fairly regard the harm as sufficiently closely related to or linked with the risk to justify a finding of liability. An illustration cited in the cases is of a mountaineer who is negligently advised by a doctor that her knee is fit to make a difficult climb. Having reached the summit, she is injured in an avalanche on the descent. But for the negligent advice, the mountaineer would not have made the climb, but the doctor will not be liable. A fair-minded person would see that the mountaineer’s injury has nothing to do with her knee: see Wallace v Kam (2013) 250 CLR 375 at 386 [24].
Thirdly, policy considerations may come into play. As the mountaineering example illustrates, a doctor is not generally liable for the materialisation of a risk beyond the doctor’s duty to warn. However, on the other hand, it is not necessarily appropriate for a doctor’s liability to extend to every injury that is the materialisation of such a risk. In Wallace v Kam, the High Court’s “normative judgment” was that a doctor who failed to warn of all the risks inherent in a proposed treatment was not liable for the materialisation of a risk that, had the warning been given, the patient would have been willing to hazard. That was because the “underlying policy” of the duty to warn is to “protect the patient from the occurrence of physical injury the risk of which is unacceptable to the patient”: at 390 [36].
In summary, causation in each case will (in the usual way) turn on the facts. As this discussion has illustrated, the facts alone will not be sufficient to demonstrate compliance with the normative “appropriateness” test under sub-section 5D(1)(b), but they do serve as a critical leaping-off point.
