David Sandiford considers the Hot Tubbing of Experts

June 24, 2021

David Sandiford

In this article, David Sandiford considers the Hot Tubbing of Experts, with reference to his involvement in a recent High Court fatal accident claim.

Working with my instructing solicitors Mills and Reeve (Birmingham), I recently concluded a very high value High Court fatal accident claim.

The claim involved complex and diverse issues on liability and quantum. The claimant and both defendants instructed experts in different disciplines including water analysis, highway engineering and accident reconstruction. Quantum was equally complex involving the likely trajectory of a post retirement medico legal career in neonatal and paediatric claims. The claimant instructed a forensic accountant and the defendants jointly instructed a similar expert.

One of the issues quite properly was raised at the pre trial review was an accurate ELH and arising from that, whether there should be hot tubbing of experts.

We should all now be familiar with the rules governing hot tubbing or concurrent expert evidence to give it its proper name. The relevant guidance is at 35PD.11 and that should always be the starting point. Hot tubbing has been used with approval in many high value personal injury claims.

Although one of the expectations (35PD.11.3) is that the hot tubbing agenda will be based on areas of disagreement in JS, one of the interesting features of our case was that as we neared trial a contentious issue arose in relation to one aspect of the evidence and we were given permission to undertake further investigations and produce a further report. That led to a further supplementary report from the experts meaning the original JS was no longer the ‘final word’ for the purposes of any hot tubbing agenda. Although strictly there ought to have been a further JS before any agenda could be considered, the trial date was coming up fast and so the focus at the PTR was upon whether there should be hot tubbing and how that should be facilitated rather than strict compliance with 35PD.11 – a good example of flexible case management.

So who should decide whether there should be hot tubbing and when should that be decided? The clear view of the very senior Judge dealing with the PTR in our case was that these were matters for the Trial Judge and it was not for a procedural Judge to make directions which would affect how the Trial Judge would run the trial. Therefore the parties were ordered to file supplementary skeleton arguments alongside their main skeleton arguments dealing with (1) the principle of concurrent expert evidence and (2) how the experts should give their evidence. On this latter issue, depending on the nature of the case, this may be truly concurrent evidence or issue by issue where  experts from like disciplines give their evidence are being 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.

So what are the pros and cons of hot tubbing? Well, it can certainly reduce an ELH and therefore costs. Also, with the Trial Judge taking the lead and initiating the discussion, an early indication may emerge of how the Trial Judge is seeing the case or what direction they are taking. On the other hand, where the expert evidence is complex and nuanced you may wish to resist hot tubbing and have experts in one or more fields give evidence consecutively in the conventional way. This is a decision to be taken collaboratively with trial counsel. They may see strategic advantages to having the freedom to ‘get in first’ and cross examine an expert in the traditional way, testing and challenging the evidence and building positions. In cross examination momentum is everything and hot tubbing may not necessarily be best suited to that in your particular case.

What is clear is that where there is an opportunity for a Judge to introduce hot tubbing, they will do so. Therefore it is something that you need to be considering very carefully at every stage and especially as you approach the PTR.

David Sandiford is a member of the Personal Injury: Defence team at Exchange Chambers. David has a large and busy higher value defendant personal injury practice. He brings over 25 years of experience of fighting and settling high value liability and quantum disputes in all types of personal injury and civil police actions.