The use of hot-tubbing in the Federal Court as well as in numerous other Australian courts is widespread. Indeed, such has been its success that other jurisdictions have adopted the practice, including the United Kingdom.  If you would like to know more about hot-tubbing, this article defines what we mean by the term and discusses the pros and cons of the practice itself.

What is Hot-tubbing?


Hot-tubbing is the practice where experts called to testify in a matter give their evidence concurrently. For this reason, it is also known as ‘concurrent evidence’ or ‘expert panels’. However, the practice involves more than experts talking together at trial. Rather, it is a methodical approach designed to isolate the areas of disagreement between the parties before trial. The process begins when:

  1. The experts engaged by the parties each prepare their report;
  2. They then exchange their report with the other experts;
  3. All the experts then meet so as to draft a joint report. This document summarises all areas of agreement and disagreement;
  4. Using the joint report as a guide, the parties prepare an agenda to guide the giving of expert evidence concurrently at trial.

At trial, the experts are both sworn in, and give evidence, together. The giving of evidence then becomes akin to a discussion. The Judge and lawyers put questions to the experts. Experts also question each other. The Judge controls and manages the process so that it remains focused and structured.

In his paper on Expert Economic Evidence, the Honourable John Middleton, Justice of the Federal Court of Australia gives a clear description of the practice of hot-tubbing:

‘It is a system that invites a series of exchanges between expert and expert and expert and lawyer, is focussed and structured if properly controlled by the judge, narrows the issues in dispute, allows the judge to assess the expert more readily, whilst allowing each party the opportunity to put and test expert evidence ‘.

Hot-tubbing in the legal context is a relatively recent development. It contrasts with the traditional adversarial approach whereby the lawyers for one party question and test the experts called by the other party individually.

Pros of Hot-tubbing

The benefits of hot-tubbing are numerous:

  • As the practice encourages experts to talk with one another before and during the trial, it more readily identifies the legal issues in dispute. That potentially helps to resolve the matter more efficiently.
  • Hot-tubbing is less confrontational than the traditional method of testing expert evidence. Experts typically feel more comfortable and are less wary of being misinterpreted at trial.
  • The process tends to hasten the length of the trial. It isolates the areas of contention between the parties before trial and therefore allows parties to discuss salient issues straight away. Isolating issues thus help to resolve cases as quickly and justly as possible.

Cons of Hot-tubbing

Although the following issues are ‘cons’, they are not disadvantages per se. With proper management, any adverse effects from them can be mitigated.

  • Hot tubbing may not reduce the overall cost of litigation. At best, it is cost neutral. As it involves a lot of logistical work by expert and lawyers, it can be costly for the parties at first instance. However, as hot-tubbing tends to shorten the length – and hence the cost of the trial – it can save the parties costs at this stage of the process.
  • The success of hot-tubbing at trial depends heavily on the presiding judge. The Judge must be able to manage the process. Of course, most Judges are skilled in that task. It only means that the process has an inbuilt margin of error. However, most courts have established procedures to minimise this risk.
  • Hot-tubbing is a change in legal tradition. While that is not necessarily a downside, it does mean that appropriate guidance must be available for practitioners to become adept at the practice.


Questions? Contact LegalVision’s litigation lawyers on 1300 544 755 to assist you.

Carole Hemingway
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