The term hot-tubbing, first coined in Australia in the 1970s, originally referred to hearing expert evidence concurrently in a panel setting.[2] Today, however, it covers a range of related practices that can allow expert witnesses to more efficiently and effectively assist the court.[3] In Canada, the most prevalent version of hot-tubbing is ordering expert witnesses to confer with each other prior to a hearing to narrow the issues and identify the points on which their views differ. The Federal Court can also engage in the other form of hot-tubbing: ordering expert witnesses to testify as a panel.[4] Such relief can be ordered by the Federal Court of Canada and by courts in Alberta, British Columbia, Ontario and Quebec.[5] By combining several rules in Ontario’s Rules of Civil Procedure, a judge may also direct experts to prepare a joint statement setting out their areas of agreement and disagreement and the reasons for it, and may even direct experts to meet in the absence of counsel.[6]

Hot-tubbing has been applauded for increasing the clarity of expert evidence, narrowing the issues in dispute, reducing trial costs and making it easier to adjudicate complicated technical evidence.[7] With these virtues in mind, the practice could be particularly valuable in wills and estates litigation.

Kates Estate

Complex expert evidence regarding capacity and undue influence often plays a critical role when a will is challenged, but competing medical opinions can be difficult for judges to assess. In fact, this very dilemma led the court to order hot-tubbing in Kates Estate as part of the trial management process. Both parties had retained psychiatrists to perform retrospective capacity assessments because the deceased’s capacity was directly at issue, having executed codicils to her will after being diagnosed with possible Alzheimer’s disease. Recognising a potential ‘precedent-setting opportunity’ after Gans J directed the expert psychiatrists to provide a file review and assessment of capacity and vulnerability to undue influence, the experts went on to provide a collaborative letter, which Gans J then used to determine whether the deceased had capacity.[8]

Looking forward

Not only is pre-trial hot-tubbing useful in the context of a will challenge but it may also be beneficial in other types of wills and estates litigation. For example, hot-tubbing focused on asset or business valuations could be used in estate matters where valuation issues are at play, such as during estate administration or the passing of accounts.