Three Big Differences in Expert Roles: UK vs US

In a recent episode of Engaging Experts, I interviewed finance expert Dr. Don Keysser, who has significant experience abroad, particularly in Great Britain. Recalling his first case in the UK, he recounts: 

I asked my attorneys, all of whom were British, “What are the protocols here?” I didn’t want to feel like a total idiot. They said, “First of all, never call the judge “Your Honor’ it’s always ‘Lord’ or ‘Your Lordship’. The first time I spoke in the courtroom to the judge, it was a bench trial, and I turned around and spoke to the judge. I started to say, “Your Honor,” then caught myself halfway through and said, “Excuse me, my Lord.” He started laughing because he knew I’m an American. He thought it was funny.  

Besides honorifics, here are three big differences between expert witnesses in the US and in the UK: 

1. Duty to the Court 

The key to the difference is the expert’s critical overriding duty to the court; the partisan expert is usually useless. -Lord Hughes of Ombersley, Justice of the Supreme Court 2013-20 

The biggest contrast between expert witnesses in the US and the UK is that of duty. In the US, an expert’s duty is not defined by the Federal Rules of Civil Procedure/Evidence. It is often stated in the US that expert witnesses’ duty is “to the truth”, while in the UK, an expert witness has a codified, formal duty to the court as defined under the Civils Rules of Procedure 35.3. In fact, UK experts must actively identify and submit any opinions held which do not support the case of the hiring party. At the end of an expert witness report, a statement must be made that the expert is aware of their duty to the court, and that such duty has been (and will continue to be) fulfilled. 

Because of this duty, in the UK, courts will often direct the parties to choose a “single joint expert” where the sides must agree on one expert, rather than bringing in opposing experts. Even when “party appointed” experts are permitted, it is done so only with the court’s permission, and at its discretion.  

In one case, Imaging forensics expert George Reis was brought in as a possible single joint expert, but became party appointed:  

The whole process was interesting. I appeared before a tribunal. When I was retained, the retaining counsel called me and said they were looking for names to present to the tribunal. The tribunal would be hiring independent experts directly. In this case, the tribunal could not decide who to hire. They brought it back to the law firms and said you guys each bring in your experts. There was no direct examination, but instead, I had 30 minutes to present my findings in whatever way I wished to do so. That was followed by an hour and a half of cross-examination. 

2. Expert Preparation 

In the US, expert witness prep can be a long and involved process. While expert witnesses must remain honest and neutral, practicing and coaching are essential trial tools.  Mock depositions and cross examinations are common, and larger actions may even warrant bringing in outside jury consultants to work with experts.  

In the UK, lawyers are bound by the Bar Standards Board (BSB), whose guidance prohibits any witness preparation beyond familiarization with the procedure, and roles of the participants in the hearing. The BSB Handbook rC9.4 states “you must not rehearse, practise with or coach a witness in respect of their evidence”.  

There are occasionally mock exercises in the UK, but they cannot be based on the case for which they are opining. They are strictly to acquaint the expert to the process: 

• 14.3 If counsel is asked to approve or participate in a mock examination-in-chief, cross-examination or re-examination, all necessary steps should be taken to satisfy oneself that the exercise is not based on facts which are the same as or similar to those of any current or impending trial, hearing or proceedings at which a participant is or is likely to be a witness. If it appears that such an exercise may not satisfy these requirements, counsel should not approve or take part in it. [emphasis added] 
• 14.4 In conducting any such mock exercises, counsel must not rehearse, practise or coach a witness in relation to his/her evidence: Rule C9.4. Where there is any reason to suspect that a mock examination-in chief, cross-examination or re-examination would or might involve a breach of the BSB Handbook, one should not approve or take part in it. 

3. Depositions 

In the UK, experts provide written witness statements or reports before the trial, similar to an expert witness report in the US. There are rarely depositions, which makes the process more streamlined but potentially less thorough. Instead, any cross-examination of experts typically occurs only during the trial itself.  

In contrast, the US discovery process provides that experts can be deposed under oath before the trial, allowing their testimony to be explored in detail during cross-examination. In this way, the parties are able to determine the strength and content of experts’ opinions prior to trial, which is critical to trial strategy.  

While both systems share a common ancestry, the US and UK legal systems have diverged with respect to expert witnesses. As the world grows smaller and more international, these differences impact experts who have the opportunity to work across the pond. Make sure that your engaging attorney has made you fully aware of any important differences that might impact your international performance.  

For over 30 years, Round Table Group has been connecting litigators with skilled and qualified expert witnesses. If you are interested in being considered for expert witness opportunities, contact us at 202-908-4500 for more information or sign up now!