I’ve never been involved in hot-tubbing as an expert witness, but I have put witnesses through the hot tub when they have appeared before me in adjudication proceedings. I didn’t call it hot-tubbing, we used the term “hot-seating”, but the result was the same.
Hot-tubbing is simply the hearing of concurrent evidence by another name. It has been around for a while now and those of us familiar with TCC litigation may recall that it was incorporated into the last revision of the TCC Guide when it was published in October 2010. It is something that Jackson LJ was keen on when he reviewed civil litigation, so much so that it was incorporated into Practice Direction (PD) 35 (the one that deals with experts) last April, when the Jackson reforms took effect.
When I used hot seating in adjudication, it was primarily to deal with witnesses of fact, as opposed to experts. Given the nature of the dispute and the complexity of the issues, the parties agreed a protocol whereby it elected a witness to occupy the hot seat. We had an agreed agenda of topics from which I chose, and then the parties elected which of their witnesses was best placed to speak to or comment on that topic. That witness then “jumped” into the hot seat to do their bit, with me questioning them. They also commented on what was said, when necessary. However, if you weren’t in the hot seat, you couldn’t speak.
It worked well in practice and it felt like we had adopted a cost-effective approach to dealing with the dispute. It enabled me to control the evidence and to ensure only one witness spoke at a time. We had a stenographer recording events, so only one person speaking at a time was important for that reason. Usually, I find that witnesses pitch in on a topic as they see fit and/or as guided by their representatives, either in response to a specific query from me or as a result of what has been said by the other side. Without careful handling, this situation can become unruly.
Shortly after writing this post, I saw that a judge in the Chancery division had hot-tubbed a witness of fact with two other experts, since that party did not have an expert witness of its own.
In Cometson and another v Merthyr Tydfil County Borough Council, the judge said that it wouldn’t usually be appropriate to do hot-tub a witness of fact, but in the interests of efficiency he allowed it (the trial estimate was inadequate and this helped to reduce the length of the trial). It also helped to keep costs down. He added that that he thought it would be helpful to hear what each of these three witnesses had to say about the many detailed matters in dispute, dealing with each topic in turn. He concluded by saying:
“In the event, I consider that the arrangements whereby these three witnesses gave evidence concurrently worked well.”
I couldn’t put it better myself.