New South Wales Consolidated Acts New South Wales Consolidated ActsA person is not compellable to give evidence on a particular matter if the court is satisfied that--
(a) substantial cost or delay would be incurred in ensuring that the person would have the capacity to understand a question about the matter or to give an answer that can be understood to a question about the matter, and
(b) adequate evidence on that matter has been given, or will be able to be given, from one or more other persons or sources.