Further, the doctrine of ex turpi causa can only be used as a defence and cannot be used to negate a duty of care, because it would inappropriately place an onus on the plaintiff to show absence of illegal or immoral conduct; the duty of care cannot be selectively applied to heads of damage; and the consideration of illegal or immoral conduct in duty of care would raise procedural problems where there are concurrent claims.
In the result, the plaintiff in this case was not seeking to profit from his illegal conduct (drinking and driving), nor was he circumventing the criminal law. However, he was contributorily negligent - therefore the damages were reduced to 50 percent.