You have decided to be an expert witness in an orthodontic malpractice case. For which side is irrelevant, but for our purposes, let’s say that you’re testifying for the defendant. The defense attorney has decided that some testimony from one of the plaintiff’s key experts will be critical to the outcome of the case, and so he asks you to sit in the courtroom gallery to listen to the testimony of the plaintiff’s expert. This will allow you to better refute his or her opinion. McAbee v Chapman , No. 2014-SC-000555-DG (KY. Sup. Ct., Dec. 15, 2016), addresses whether an expert for 1 party should be allowed to sit in the courtroom and hear the testimony of the expert for the opposing party.

Kentucky Rule of Evidence (KRE) 615 governs this issue, and it states the following.

At the request of a party the court shall order witnesses excluded so they cannot hear the testimony of other witnesses…This rule does not authorize the exclusion of…(3) [a] person whose presence is shown by a party to be essential to the presentation of the party’s cause.

The facts of the case are that the plaintiff needed an anastomosis of her colon. This procedure is quite involved, and the court went into great operative detail by discussing every technicality. Somehow during the surgery, a fistula was created between the patient’s bladder and rectum, allowing discharge from each organ to flow into the other. The patient underwent multiple surgeries over many months in attempts to correct the problem, all to no avail. She was eventually retreated at a major teaching hospital, where additional surgical procedures were performed, and the situation was corrected. There remained some residual problems, not major, but impacting enough on her lifestyle that her work suffered, resulting in a loss of income. The plaintiff filed a negligence claim against the first surgeon for having breached the standard of care regarding his performance of certain aspects of the initial surgery.

The trial consisted in part of a typical “battle of the experts.” The plaintiff’s expert claimed that the original surgery was performed improperly based on a number of technical errors. The defense experts claimed that the surgery was performed within the standard of care, and that the injuries were an unfortunate consequence that happens in a small percentage of cases. At trial, the jury returned a 9-to-3 defense verdict that the plaintiff appealed. Her contention was that the court erred when it did not grant her motion to have the defendant’s experts excluded from the courtroom during the testimony of her experts, in accordance with KRE 615. Essentially, the claim is that the defendant’s experts had an unfair advantage. The court of appeals affirmed the trial court’s ruling, and this appeal to the Kentucky Supreme Court ensued.

The Supreme Court noted that the purpose of KRE 615 is so that witnesses cannot hear the testimony of other witnesses. This to a large part prevents them from altering their own testimony based on what they heard other witnesses say. The court noted that separation of witnesses is a common technique that crosses all professions and callings, and has been used for thousands of years. Police departments separate witnesses to crimes and interview them separately, and Daniel vindicated Susanna of adultery in the Bible (Daniel, chapter 13) by separating her accusers, resulting in inconsistent testimonies. Citing John Wigmore ( Wigmore on Evidence , 4th ed. Alphen aan den Rijn, Netherlands: Wolters Kluwer; 2007), one of the most famous legal scholars on evidence, the court stated that “separation of witnesses is, next to cross-examination, one of the greatest engines that the skill of man has ever invented for the detection of liars in a court of justice.”

Returning to the case, the court noted that in opposing the plaintiff’s motion for the witnesses to be sequestered, if the defendant needed an expert to be present, it could always show that the expert’s presence was “essential to their presentation of the case” as per the third exemption in the statute. After a protracted sidebar discussion, the trial court ruled against the plaintiff’s motion for sequestration and held that all experts for both sides could be present. The court opined that allowing them to listen to their conflicting testimonies and then commenting in their expert opinions would inevitably be helpful to the jury.

Upon appeal, the plaintiff argued that the defendant did not make a “showing” as to why the attendance of their witness was “essential” to their presentation of the case. The appellate court based its ruling to uphold that of the trial court on the argument that the expert’s attendance was essential because “an expert need[s] to advise counsel in the management of litigation.” The appellate court, in support of its decision, noted that “expert testimony” is less subject to “falsity, inaccuracy, and collusion” than testimony from a “fact witness.”

In stating its opposition to the finding of the court of appeals, the Kentucky Supreme Court agreed with the sentiments advocated by other courts that the attempt of many trial courts

to try to frame expert testimony as a debate, point and counterpoint, between experts is not an improvement over “the time-honored tradition” of each expert setting forth his or her opinion, subject to cross examination, by opposing counsel, with the jury then determining the more credible view. (Cit. Omit.)

The Supreme Court noted that a “showing” needs to be more than 1 party stating that the expert’s presence is simply “desirable” or “helpful” or “important.” The “showing” needs to be based on the witness’s need to be present in the courtroom such as when the opposing testimony is highly convoluted and technical and it would be “essential” to assist counsel in understanding those technicalities. In addition, there may be times when, to adequately understand the facts of a case, one must hear the testimony of other witnesses. However, in this case, since all experts were deposed and the depositions were available to the opposing experts before trial, and deviations from the deposition testimony were not expected, and since the expert could deduce the facts from the depositions and the plaintiff’s medical records, there was no “showing” that rose to the level of requiring an exemption from sequestration.

The supreme court noted that

the important factors in the harmless error analysis are the relative importance of the non-sequestered witness’s testimony and the likely effect on that testimony of the prior testimony by others…In expert witness cases, the situation is somewhat different.…Asking an expert witness about facts testified to by the parties or opinions rendered by opposing experts is simply standard procedure. In such cases, therefore, the harmless error analysis is not simply whether the erroneously non-sequestered expert’s testimony was affected in any way by the testimony of others—it clearly will have been—but rather whether it was improperly affected.

The court stated that it is the obligation of reviewing courts to “disregard trial errors and defects that do not affect the substantial rights of the parties.” The reviewing court needs only to be persuaded that “with fair assurance…the judgment was not substantially swayed by the error.” The court agreed with the plaintiff that the trial court abused its discretion in allowing the opposing expert to be present; but it also held that the error was not a substantial factor in the jury’s decision thus constituted what is known as “harmless error.” It affirmed the dismissals by the lower courts, thus upholding the resolution in favor of the defendant.