Bubbles or Troubles? “Hot Tubbing” for Experts

By Noah Bolmer 

Despite the relaxing name, “hot tubbing” does not refer to expert witnesses relaxing in a jacuzzi. Formally known as concurrent expert evidence (CEE), concurrent expert testimony (CET), or witness conferencing (among others); the practice entails experts simultaneously testifying before the fact finder. Typically, a judge or panel of judges questions the expert group, rather than the usual sequential calling of experts for each side. 

Background 

Starting in Australia in the 1970s, before gaining adoption into England and beyond, the practice would arise to help combat expert witness bias or the perception thereof—as well as enhancing efficiency. The Federal Court of Australia, (citing case 1971-2-NSWLR-278) states:  

By attending to the progress of this argumentative process … the court is enabled to perceive and more readily to appreciate the points of similarity and dissimilarity. In this way the tendering of expert evidence is of value in exposing the facets of the ultimate question to which the expert opinion evidence is directed. 

In other words, even though experts are (typically) still hired and prepared by each side to the matter, the belief is the fact-finder is better able to see through bias when experts freely converse.  

By 2003, CEE had made its way to the states, and shortly thereafter, it has been used—albeit in a limited fashion—in numerous settings including Federal Claims Court, Daubert hearings, and a patent infringement case. While the practice has become codified in many Australian jurisdictions, its use in the states remains informal, and at the discretion of judges. Law firm Jones Day states that the practice is probably compatible with the Federal Rules of Evidence, stating: 

To date, no reported decision of an American court has examined the compatibility of the concurrent expert evidence technique with civil rules of procedure or evidence [. . .] while they do not specifically sanction the practice, [they] provide a framework in which the concurrent expert evidence technique seems to fit. Rule 611, for example, gives trial courts “control over the mode and order of examining witnesses and presenting evidence so as to,” among other things, “make those procedures effective for determining the truth” and “avoid wasting time.”[. . .] As long as cross-examination rights are preserved, the use of the concurrent expert testimony technique appears to be a matter of a trial court’s discretion reviewed only for abuse of discretion under the circumstances of a particular case. 

Importantly, as stated above, U.S. implementations are hybrid; preserving cross-examination, even when a judge uses CEE. This may require additional expert preparation in order to be ready for both types of examination.  

Process 

While the specifics of CEE vary by jurisdiction and matter, the general principles remain consistent. The experts may be hired by each side as is typical, or they may even be appointed by the court, as is common in UK jurisprudence. Occasionally, experts will have the opportunity to present their opinion on the matter to be discussed, prior to the hot tub. Next, rather than—or in addition to—the typical cycle of direct examination, cross examination, and redirect; CEE is a direct conversation between the experts, with the presiding judge, arbitrator, or panel interrupting with questions. This guides the discussion between the sides, until they reach a mutual conclusion, or until the fact finder is convinced. In jurisdictions which maintain cross-examination, a hot tub may be conducted at any point of the trial; either prior, or subsequent examination at the judge’s discretion.  

Beyond trials, CEE might be used in alternative dispute resolution mechanisms, like arbitration. Industrial technology expert Mike Slinn describes his CEE experience before the International Court of Arbitration in Paris, France: 

This was a tribunal of five judges that I had to present in front of. There were seven experts on our side and there was one expert—myself—who would speak for the combined opinion of all of us. At the end of the case, there was only one expert for the other side. This other expert and myself were brought before the tribunal of five [where] they fired questions at us and we had an opportunity to respond free-form. We would start by letting each other speak, and then sometimes we would get into interrupting and discussion—and this is what the tribunal wanted. They wanted to [get to] the real truth, and they were just going to grill us until we believed something was right. [. . .] You had to be fast on your feet and confident in your facts to be able to say things. The other expert was over-confident. He was confident to the point of being cocky, and he said some really stupid things and I capitalized on that. 

Like typical adversarial expert witness work, preparation and experience is still paramount. He continues: 

It was a unique opportunity, so I think being a musician and being comfortable performing to an audience—which I have been doing for 50 years—stood me in good stead, because to me it is [just] another audience and I’ve got my material. I practice and I know it. We were up until 2:00 in the morning going over material and the attorneys on my side had a mini tribunal [. . .] I failed a lot in front of them, but that was okay because they would coach me. When the real thing came, it was easier than what [the mock tribunal] had put me through. They deliberately over-practiced, and that is the way to do it. Nothing succeeds like excess. 

Advantages 

In a typical courtroom, an expert is asked questions only by attorneys, who are not usually subject-matter experts. The loop of direct, cross, and redirect has the attorney acting as a go-between; the experts never directly communicate. CEE eliminates the middleman. The experts are able to converse, argue, or agree on points—with the judge keeping the discussion focused and on-track. Ostensibly, this helps eliminate the effects of trick questions, traps, and other non-substantive techniques that attorneys employee for their clients. While the American judicial system has backstops in place to mitigate those concerns—objections and redirects for instance—CEE bypasses the issue entirely. 

As hot tubbing is typically (although not exclusively) in a bench trial or arbitration format, CEE has an efficiency advantage. The judge knows what information they need to reach a conclusion, and is the person guiding the expert discussion and asking questions. If anything is unclear, it is a simple matter of asking the experts directly, rather than hoping the concern is elucidated through examination. Moreover, expert witnesses are afforded more time and latitude than during examination, where their responses would be limited to the questions asked. They are free to take the time to explain their opinion, while directly criticizing—or even agreeing with—the other witness’s responses. 

Additionally, the contemporaneous nature of the testimony may allow the fact finder to better “follow along” with each side’s points, rather than hearing the entirety of one expert’s testimony, followed by the next, and then starting over if a witness is recalled. This also has the potential to reduce the amount of time spent on expert testimony.  

Disadvantages 

While the advantages of CEE are numerous, there are potential pitfalls. Without a body of U.S. law to rely upon, judges must use an abundance of discretion and caution. The practice has not been adjudicated nor codified, so allowing hot tubs might eventually lead to appeals or dismissals. If an attorney or expert witness objects to the process, the judge must carefully consider whether to press forward. 

Expert preparation—a topic with a great deal of research behind it—might be substantially different for CEE. Typical preparation techniques may be less effective or need modification, which could result in additional costs for the trial team. In fact, one Australian legal services company considers the practice more expensive, or cost neutral at best.  

Asking questions of, and impeaching witnesses is primarily the job of attorneys (rebuttal reports notwithstanding), but CEE may place some of that work on to experts. This potentially diminished role means that there may be some topics or points which the attorney would have preferred to be addressed, that the expert witness does not have the opportunity to opine upon in open court.  

When one expert says something that the other doesn’t agree with, the hot tub becomes a debate forum—which may be an advantage or disadvantage—depending on the expert. CEE favors experts that are more proactive, quick-thinking, and well-spoken over those that prefer to more carefully consider each point before speaking.  

Conclusion 

As CEE gains popularity, experts and attorneys should be aware of the overall process and potential obstacles. If you are called for a soak in the hot tub, be prepared for a unique back-and-forth with your counterpart and work with your attorney to hone your debate skills for an effective performance at trial. As with any testimonial opportunity, solid preparation is key. 

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!