May a medical expert witness switch sides in a lawsuit? Unlike the lawyers in a case, no rule expressly stops a medical expert from "hopping the fence." After all, the conventional wisdom is that the expert's allegiance is to the truth, not to any one party. But just because an expert has the opportunity to switch sides doesn't necessarily make it the right thing to do. Switching sides can have adverse consequences. For one, the expert could be disqualified. For another, the lawyer could be sanctioned. And if either of those happens, the medical malpractice case could be nonsuited.
Yet, judging by the reported cases and the comments of lawyers, it happens with surprising frequency. What is a typical scenario? Let's say that the plaintiff lawyer hires a medical expert and after reviewing the file the expert finds the attorney's case non-meritorious. The plaintiff attorney then discharges the expert, and within a few short days the defense hires that same medical expert. In those instances most courts interested in preserving confidentiality and privilege will keep side-switching experts from taking the witness stand. And if a court finds that a lawyer inappropriately lured an expert from his adversary's side to his, the court can impose severe sanctions on the attorney.
But perhaps it is not all bad. Some attorneys see an opportunity when an expert switches sides. They see it as an opening to question credibility – not of the expert, but of the lawyer who discharged the expert and the integrity of that lawyer's underlying case. Experts are required to give an honest professional assessment opinion on issues and not consider the party that hired them when providing their opinions. When they do this the process works as it should. When the attorney who hired the medical expert chooses to ignore the opinion given and then shop for a new expert, that is where ethical considerations come into play – not as to the expert, rather to the lawyer involved.
But consider this: There are two kinds of experts who will switch sides. The first is the honest expert, the expert who cannot be bought. This expert remains consistent in the positions he takes, no matter who he is working for. The other is the expert who lacks scruples. This expert's opinion is for sale. These are the experts who will advocate on behalf of whichever party is paying their check. If switching sides is in their best interest, they will. They are consistent in looking out for themselves first, making the truth a casualty. These are the so-called "hired guns."
Expert side-switching comes up with enough regularity that courts have set standards for deciding whether to disqualify the side-switching expert. Most apply the two-part test set out by the 5th U.S. Circuit Court of Appeals in a 1996 decision, Koch Refining Co. v. Jennifer L. Boudreaux MV, 85 F.3d 1178. First, is it objectively reasonable for any first party who claims to have retained the expert to conclude that a confidential relationship existed? And second, was any confidential or privileged information disclosed by the first party to the expert? Only if the answers to both questions are affirmative can the witness be disqualified.
Regarding attorney sanctions, the attorney who absconds with the other side's expert not only risks his own case, but puts that expert into the unenviable position of losing future credibility. Future attorney clients may attribute fault to the expert and be less likely to hire the expert for new cases. If an expert switches sides, it could be an uphill climb to re-establish credibility. It could be interpreted that the other side released the expert with good reason to do so. That is the conundrum a medical expert faces when considering whether or not he should switch sides.