Concurrent Evidence

Concurrent evidence, or hot–tubbing as it is also called, is a measure that is being introduced (see below) to help reduce the costs associated with expert evidence. Concurrent evidence has been very successfully used in the Australian Courts as well as in arbitration and has recently been introduced through the CPR to England & Wales Civil Courts.

It is described by the Hon Justice Peter McClellan (Chief Judge at Common Law of the Supreme Court of New South Wales), a keen promoter of the process, as:

a discussion chaired by the judge in which the various experts, the parties, the advocates and the judge engage in a co-operative endeavour to identify the issues and arrive where possible at a common resolution of them. Where resolution of issues is not possible, a structured discussion, with the judge as chairperson, allows the experts to give their opinions without the constraints of the adversarial process and in a forum which enables them to respond directly to each other. The judge is not confined to the opinion of one advisor but has the benefit of multiple advisers who are rigorously examined in public.”

Prior to a hearing taking place experts (in Civil Cases) often take part in a meeting of experts and prepare a joint statement which is provided to the judge. The Joint Statement is then used to produce an agreed agenda with a numbered list of the issues on which the experts disagree on and is provided to the Judge in time for proper consideration.

Usually in the adversarial system the Experts would then be cross-examined in Court. With hot-tubbing, however, the experts are sworn in together (rather than separately) at the hearing and the Judge then chairs what is effectively a discussion of the issues in disagreement. When this occurs there is no cross-examination of the experts.

At the end of the hot-tubbing process the Judge may seek to summarise the experts’ positions on the issues and then ask the experts to confirm or correct the summary. Hot Tubbing, having been introduced on an experimental basis, is now relatively commonplace.

CPR PD35 gives the court the power to order concurrent evidence/hot-tubbing by allowing it to direct that expert witnesses from like disciplines can give their evidence concurrently. It also sets out the procedure to be followed once such a direction has been given.

The Practice Direction 35.11 states:

Concurrent expert evidence

11.1 At any stage in the proceedings the court may direct that some or all of the evidence of experts from like disciplines shall be given concurrently. The procedure set out in paragraph 11.4 shall apply in respect of any part of the evidence which is to be given concurrently.

11.2 To the extent that the expert evidence is not to be given concurrently, the court may direct the evidence to be given in any appropriate manner. This may include a direction for the experts from like disciplines to give their evidence and be cross-examined on an issue-by-issue basis, so that each party calls its expert or experts to give evidence in relation to a particular issue, followed by the other parties calling their expert or experts to give evidence in relation to that issue (and so on for each of the expert issues which are to be addressed in this manner).

11.3 The court may set an agenda for the taking of expert evidence concurrently or on an issue-by-issue basis, or may direct that the parties agree such an agenda subject to the approval of the court. In either case, the agenda should be based upon the areas of disagreement identified in the experts’ joint statements made pursuant to rule 35.12.

11.4 Where expert evidence is to be given concurrently, then (after the relevant experts have each taken the oath or affirmed) in relation to each issue on the agenda, and subject to the judge’s discretion to modify the procedure—

(1) the judge will initiate the discussion by asking the experts, in turn, for their views in relation to the issues on the agenda. Once an expert has expressed a view the judge may ask questions about it. At one or more appropriate stages when questioning a particular expert, the judge may invite the other expert to comment or to ask that expert’s own questions of the first expert;

(2) after the process set out in (1) has been completed for any issue (or all issues), the judge will invite the parties’ representatives to ask questions of the experts. Such questioning should be directed towards:

(a) testing the correctness of an expert’s view;

(b) seeking clarification of an expert’s view; or

(c) eliciting evidence on any issue (or on any aspect of an issue) which has been omitted from consideration during the process set out in (1); and

(3) after the process set out in (2) has been completed in relation to any issue (or all issues), the judge may summarise the experts’ different positions on the issue and ask them to confirm or correct that summary.

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