Winston v Roach

In *Winston v Roach*, heard in the Court of Appeal of New South Wales, the appeal concerned the assessment of damages for a motor accident where liability was not in dispute. The central issue revolved around the extent to which an existing back condition, along with psychiatric and other difficulties, had been exacerbated by the accident, and whether the damages awarded adequately accounted for this.

The court was required to determine the principles governing the assessment of damages when a plaintiff suffers from pre-existing conditions that are aggravated by the defendant's negligence. Specifically, the court considered the legal onus of proof in such circumstances and the extent to which a tortfeasor is responsible only for the damage they have caused, as opposed to pre-existing or unrelated conditions.

Mason P and Santow JA reasoned that while the defendant is liable for the aggravation of a pre-existing condition, they are not responsible for the underlying condition itself. The court applied the principle that the plaintiff bears the onus of proving the extent of the aggravation caused by the accident. The damages awarded must reflect the difference between the plaintiff's condition before the accident and their condition after the accident, attributable solely to the negligent act.

The appeal was upheld in part, indicating that the court found some merit in the grounds of appeal concerning the assessment of damages.