First a Failure to Inform, then a Failure to Listen: Why the plaintiff’s evidence about what they would have done should not be inadmissible in failure to inform cases

In negligent failure to inform cases, the plaintiff must prove that the harm complained of would not have materialised if they had been properly informed. This aspect of factual causation ordinarily necessitates an inquiry into what the plaintiff would have done in a hypothetical scenario which never arose, making the plaintiff’s evidence on this point vulnerable to hindsight bias. This concern led the common law in Australia to treat it with great caution and, following the Review of the Law of Negligence, the civil liability legislation in several jurisdictions to make it inadmissible. This article contends that this statutory prohibition is ill-founded because it is inconsistent with a subjective approach to determining causation; it disregards the potential utility of the plaintiff’s evidence on this point; and it is unjustifiable when hindsight evidence can be given by the plaintiff as to inquiries other than causation, and by witnesses other than the plaintiff. It is concluded that legislative bans on the plaintiff giving evidence about what they would have done should be repealed, and that whilst courts are correct to treat this evidence with caution in most cases, they are well-equipped to do exactly that.