TB and DC v State of New South Wales

The case before the court involved a dispute between the plaintiffs, TB and DC, and the State of New South Wales. The plaintiffs sought compensation for injuries sustained during an operation performed by the defendant. The dispute centred on the admissibility of expert medical opinion evidence, specifically whether the assumptions made by the expert about the plaintiff's medical history were supported by evidence. The matter was heard in the Supreme Court of New South Wales.

The central legal issue in the case was whether the common law rule in Ramsay v Watson, which concerns the admissibility of expert evidence based on unsupported assumptions, applies to the Evidence Act 1995 (NSW). The court needed to determine if the assumptions made by the expert witness regarding the plaintiff's medical history were sufficiently supported by evidence, and if not, whether this rendered the expert opinion inadmissible. This question required a careful examination of both the common law precedent and the statutory provisions of the Evidence Act.

The court examined the common law principle established in Ramsay v Watson, which states that expert evidence based on assumptions unsupported by evidence is inadmissible. The court then considered whether this principle was incorporated into the Evidence Act 1995 (NSW). After reviewing the statutory provisions and relevant case law, the court concluded that the common law rule did apply to the Evidence Act. The assumptions made by the expert in this case were not supported by evidence, leading to the conclusion that the expert's report was inadmissible. Consequently, the plaintiffs' claims were dismissed due to the lack of admissible expert evidence.

The final orders of the court were that the plaintiffs' claims were dismissed. The court ruled that the expert's assumptions regarding the plaintiff's medical history were not supported by evidence, rendering the expert's report inadmissible under the Evidence Act. As a result, the plaintiffs were not able to establish their case, and the defendant's motion for summary dismissal was granted.