Concurrent expert evidence ("hot-tubbing") recommended as optional procedure

An interim report on the Manchester concurrent evidence pilot has concluded that this technique should be available as an optional procedure which can be adopted if the judge so directs (i.e. whether or not the parties agree).

The technique, which developed in Australia and is known colloquially as "hot-tubbing", involves hearing evidence concurrently from the experts in any particular discipline. At trial, the experts are sworn in at the same time and the judge chairs a discussion between the experts. Counsel join in the discussion and can put questions to the experts, as and when permitted by the judge, and the experts can put questions to each other.  

The pilot

Lord Justice Jackson's final report following his costs review noted that "hot tubbing" had met with a mixed response during the consultation period. He suggested that the technique should be piloted in cases where the experts, the lawyers and the judge consent.

A pilot scheme was commenced in the Manchester Technology and Construction Court and Mercantile Court, in which judges identified suitable cases and invited the parties to adopt the procedure at trial. Under the pilot guidelines, the procedure was not to be recommended where the credibility or independence of any of the experts was in doubt. Although the parties in some 18 cases agreed to adopt the procedure, it has only been used at trial in three cases (the rest having settled or, in a few cases, not yet come to trial). The analysis in the interim report is therefore based on questionnaires completed by the judge, solicitors, barristers and experts in only three cases - which, the author frankly admits, is insufficient data on which to reach solid conclusions on the effectiveness of the procedure.

The conclusions

However, the report states, the evidence of the pilot to date suggests that there are time and quality benefits to be gained from the use of the technique, particularly due to the efficiency of the process and the ease with which the evidence can be given and differences of view examined and assessed. The report states "As a procedure for enhancing the quality of judicial decision-making there seem to be significant benefits." It is less clear whether there are benefits in terms of rigour (with counsel generally considering the process less rigorous than traditional cross-examination), expert objectivity, or costs savings.

Whilst recognising that more evidence is needed before firm conclusions can be drawn, the report recommends that in light of the positive evaluations of those involved in the pilot to date, and the relatively large number of other cases in which parties agreed to adopt the procedure, the use of concurrent evidence should be included in the Part 35 practice direction as an optional procedure to be adopted at the direction of the judge.

Comment

It will be interesting to see the extent to which judges direct the use of concurrent evidence where the parties have not raised the issue, or indeed oppose the use of technique. In any event, assuming the procedure is incorporated in the Part 35 practice direction as the interim report recommends, parties will wish to be aware of the technique so that they can address its suitability (or otherwise) in any given case.