If you have read my previous articles in this publication, much of what follows will be familiar. But please read on, because I have tried to set out briefly, and after many years of bitter experience as an expert, some helpful comments and guidance for experts and those – you – who instruct them.
1 Don’t let your expert become too friendly
An expert must at all times be very aware of CPR 35.3(2) (other rules are available for criminal and family lawyers) that the expert has a duty to the court, overriding any duty to those instructing them or who are paying them. Be aware of Vernon -v- Bosley (No 1)  where Thorpe LJ talked of plaintiff and defendant walking down either side of the road, but the expert must be “…ever mindful of the need to walk straight down the middle of the road and to resist the temptation to join the party from whom his instructions come on the pavement.”
A more recent lesson comes from Mostyn J (with whom I worked when he was at the bar – it was fun) in Gallagher -v- Gallagher (No 2) (Financial Remedies) 2022 EWFC 53 where the judge took the view that the expert Singleton lacked the impartiality required of an expert witness. He acted in a “strategic defensive manner” that had “all the hallmarks of the mentality of an advocate.” His behaviour was “highly suggestive of de facto membership of the husband’s team.”
Such behaviour cannot have helped the team which Singleton thought he was playing for. Experts can be polite and helpful, but don’t expect them to be bestie friends.
2 Experts attending mediations
I can comment on this as both expert and as mediator.
If an expert does attend a mediation, they must walk a very fine line. The atmosphere in a mediation is very different from the courtroom. At mediation, everyone is friendly (usually) on first name terms (usually) and willing to reach compromises (occasionally!). What part should an expert play in this? In my view, no part at all. If there were complex matters within the experts’ expertise, they should have hammered those out beforehand and produced a joint statement, however informal.
Where I see a pair of experts at my mediations, I ask them to hold a joint meeting in a side room – they should have done this beforehand – and keep them out of the way. Mediation is “big picture” and broad brush; detailed figurework just wastes time and should have been done beforehand.
And if the expert does participate in the discussions, it is difficult for him/her to appear impartial, to demonstrate from the witness box that overriding duty to the court, if the mediation should fail and formal litigation ensue.
Anything said and heard at mediation is confidential, of course, but it is particularly unhelpful if an expert were to say one thing at mediation and something quite different at trial. It is safer to keep your experts away; perhaps available for telephone help, but not participating in the discussions.
3 Meetings of experts
As with most stages of litigation where experts are involved, there is no substitute for engaging an expert who, as well as being outstanding in their profession, has taken the trouble to learn how to be a member of the second profession – of expert. The Academy of Experts and the Expert Witness Institute teach this second profession very well.
This is particularly important with meetings of experts. Instructing solicitors and even judges can have a hand in preparing the agenda for such a meeting, but in my experience after many hundreds of these meetings, they never do. And why should they? The opposing experts have produced their reports, the differences are obvious, and there’s your agenda.
And never, ever, interfere in the drafting of the joint statement. This must be the work of the experts; it becomes part of their evidence in chief.
There is a strident example of how this can go wrong in Patricia Andrews & Ors -v- Kronospan Ltd  EWHC 479 which I discuss at length in my blog. It’s a good read, but in essence one expert worked closely with instructing solicitor for two years beyond the date for filing of the joint statement, charged £225,000 (far more than I have ever charged!) and had their evidence excluded. The client would have been left without expert, except that the trial date had not been fixed and the judge found that a new expert could start again, and the waste of time could be reflected in costs. What a waste!
Finally to privilege. Be very careful what you disclose regarding instruction of experts.
In Pickett -v- Balkind  EWHC 2226 (TTC) a letter from an expert was presented to the court by the claimant’s lawyers to support an adjournment of the trial because of the expert’s ill health. Unhelpfully, the first four paragraphs of that letter raised questions regarding that expert’s independence. The claimant’s lawyers asked for those four paragraphs to be regarded as privileged. The judge refused the application, and ordered that the expert should be cross-examined at trial. That would not have been comfortable for him, and would probably have not helped the claimant.
Litigation is complicated enough for lawyers, but when choosing your experts, recognise that their job is complicated, too, so don’t choose an enthusiastic amateur. And better yet (as the Americans would say) choose the expert yourself with care; don’t leave it to the office junior (it happens!)