Can Expert Witnesses Change their Minds?

By Mike Nelson

Yes, but a recent decision from the Tenth Circuit Court of Appeals suggests there is a right and wrong way to do so.  

In the fascinating case of Pace v. Swerdlow, the plaintiffs sued a medical expert that they themselves had retained in an underlying medical malpractice case. In the underlying case, the expert previously testified favorably for the plaintiffs, before dramatically reversing his opinion on the eve of the summary judgment hearing. While every state grants expert witnesses immunity from suits initiated by the opposing side, same-side (“friendly”) expert immunity remains an open question in many jurisdictions.    

The Federal District Court for the District of Utah dismissed the case, holding that the expert’s change of opinion had not proximately caused the plaintiffs to lose the underlying medical malpractice case. The Tenth Circuit reversed the district court on the causation issue, holding that the plaintiffs had alleged facts which, if proved, would establish the element of proximate cause in their claim against the expert.  

In allowing the claim to proceed, the Tenth Circuit questioned the expert’s decision to wait until the eve of the summary judgment hearing to communicate his change of opinion, and pointed to allegations that the expert changed his opinion out of fear and intimidation, and not – as the expert claimed – because a compelling new piece of medical evidence had been brought to his attention. 

The decision to recognize a cause-of-action for friendly expert negligence remains a matter of state law, as do the contours of such an action. However, the proximate cause analysis in Pace, having come from the Tenth Circuit, will likely be regarded as considerable persuasive authority by courts assessing causation in future claims of friendly expert negligence involving a change of opinion by the expert.  

For further analysis of this interesting case see: Michael Nelson, Pace v. Swerdlow: Can Expert Witnesses Face Liability for Changing Their Minds? The Tenth Circuit Weighs in on the Element of Proximate Cause in a Claim of Expert Negligence, 86 Denv. U. L. Rev. 1199 (2009).