Macquarie International Health Clinic Pty Ltd v Sydney Local Health District; Sydney Local Health District v Macquarie Health Corporation Ltd (No 10)

The case before the court involved Macquarie International Health Clinic Pty Ltd and Sydney Local Health District, with Macquarie Health Corporation Ltd also a party to the second appeal. The dispute centred around the termination of a 103-year lease by the defendant, Sydney Local Health District, for the purpose of constructing a private hospital and a car park. At the time of the dispossession, the car park was operational, but the private hospital had not yet been built. The dispossession lasted for 15 years. The primary issue for the court was to determine the appropriate method for calculating mesne profits, specifically the application of the user principle, given the unique circumstances of the case.

The court had to decide whether the expert opinion presented by the plaintiff was admissible under the Evidence Act 1995 (NSW). The plaintiff’s expert, referred to as Expert A, adopted and was fortified by the opinions of another expert, Expert B. However, Expert A did not disclose how they applied Expert B's opinion in their reasoning. The court needed to assess whether this was sufficient to make Expert B's opinions admissible, considering sections 55, 56(2), 60, 79, 135, and 136 of the Evidence Act.

In determining the admissibility of the expert opinion, the court found that the lack of disclosure on how Expert A applied Expert B’s opinion was critical. The court held that for the expert opinion to be admissible, Expert A needed to explain how they integrated and applied Expert B’s opinion in their analysis. The court ruled that without this clarification, the expert opinion was not sufficiently reliable to be admitted as evidence. Consequently, the court dismissed the appeal and affirmed the original decision regarding the calculation of mesne profits.