‘Hot tubbing’: is concurrent expert evidence working?

Last month the Civil Justice Council published a report on ‘hot tubbing’ – or more broadly, ‘concurrent expert evidence’ (CEE) – looking at how courts have actually been using the practice.

The report canvassed views from judges, lawyers and experts who have been involved in CEE, and its findings were very informative.

The CJC identified different ways in which the courts are adopting concurrent expert evidence. Some are using the pure ‘hot tub’ approach, where the judge leads an examination of several different experts, in the same session. Other judges are examining experts in ‘back to back’ sessions.

There is a broad range of practice in terms of the extent to which counsel are able to cross-examine the experts, and the degree to which the judge takes the reins in leading the questioning.

So how successful is concurrent expert evidence actually proving?

The report found that judges are convinced CEE is improving the quality of expert evidence; and lawyers — and to a lesser extent, experts — also agree.

According to some of the comments made by respondents to a CJC survey on the topic, the process works best where the experts being questioned are of a similar level of seniority. One respondent noted that ‘the status of the expert can affect the way in which the hot tub proceeds. In one case one expert was deferential to a more senior colleague’.

Another respondent suggested that ‘experts tend to be much more forthcoming in tribunal-led questioning, because they feel like they are being asked to assist, rather than being attacked. You get less guarded answers.’

But some lawyers did warn that tribunal-led questioning can be less rigorous than a grilling from counsel, with the danger that it ‘lets very poor experts off the hook from a searching cross-examination’.

One respondent commented: ‘Witnesses who were obviously “schooled up” as to the issues in play, or who are more willing to advocate, perform better in a hot tub. It seems that judges find it more difficult to discern schooled-up experts in a hot tub environment than in a conventional cross examination.’

The CJC noted that there is ‘a potential danger to the administration of justice for either party, if counsel is not given sufficient opportunity to test the opposing expert’s view’ – and this is something that it suggests should be dealt with in a new guidance note on concurrent expert evidence for judges and practitioners, and a revised practice direction.

What about costs: does concurrent evidence actually save any money, for parties or for the public purse? Not necessarily.

The judges questioned tended to think that concurrent evidence had saved trial time but had increased the hours needed for preparation. Lawyers were less convinced that trial time had been saved – it seemed to depend on the level of cross-examination that had been allowed before or after the hot tub.

CEE does nothing to reduce the amount of preparation time needed by barristers. As counsel will often have no idea until the session begins just how involved they will actually be in the hot tub, or how much chance they will have to examine experts afterwards, they still need to do the same level of preparation as usual.

But even if preparation time is increased, if there really is a reduction in the length of the trial, that is likely to save money overall. As Lord Justice Jackson said in a speech on CEE in June, ’Although views differ on the question of costs saving, most English judges and practitioners agree that CEE leads to a saving of time at trial. Since trial time is the most expensive component of litigation, this is a valuable saving.’

In a message to the profession, he added: ’Solicitors who are striving to bring the actual costs of litigation closer to the approved budget should give serious consideration to proposing the use of CEE’.

The CJC report, then, shows that concurrent expert evidence is well liked by the judges who have used it, and broadly welcomed by the lawyers who have experience of it.

At the moment that is a small minority of the profession, but surely its use is set to rise.

As one lawyer who responded to the CJC’s research put it: ‘Hot tubbing is not something to be afraid of. Indeed, used properly, it could work to the client’s tactical advantage. As with all things in litigation, the key is preparation.’

Rachel Rothwell is editor of Gazette sister publication Litigation Funding

Follow Rachel on Twitter: @LawJourno