Applicability of Immunity for “Friendly Experts” Witness Testimony


The so-called “friendly experts” hired specially to provide opinion testimony in litigation are not entitled to immunity for their work in preparing and communicating their opinions. Some jurisdictions have analyzed whether the policy arguments used to justify the witness immunity doctrine apply in the situation of a claim against an expert hired by a client in the subject matter. The court concluded that the purpose of encouraging straightforward testimony in court does not further immunity to the incompetence of “friendly experts” just because they provide expert services.

The so-called "friendly experts" immunity

The so-called “friendly experts” are not entitled to immunity for their opinion testimony in litigation.

The majority of states, including California, Connecticut, Louisiana, Massachusetts, Missouri and Pennsylvania held that hired expert witnesses are not immune from being sued by their client based on the difference between the expert’s testimony and the pretrial work performed for that testimony. So, experts that failed to perform accordingly to scientific methods or theories may confront malpractice claims against them since expert witnesses are usually retained to provide expert services, such as testimony in relation to judicial proceedings. In this regard, the court also determined that “there must be a nexus between the alleged immunity, the fact-finding function of the courts and the importance in having an expert to speak freely.”

In other jurisdictions, such as New Jersey and Vermont, appointed expert witnesses may face liability based on negligent performance regarding their professional work. In addition, some other courts allow adverse expert witnesses to be sued. In California and New York, attorneys may be liable for their expert witness negligence. Although, Michigan and Tennessee protect expert witness’s immunity, in Michigan, courts only protect expert witnesses’ testimony but not their expert opinions.

With regard to disciplinary actions for untrustworthy testimony given by an expert witness, the court determined that immunity does not apply in such cases; even in jurisdictions that afford expert witness immunity because of the difference between an expert being sued in a civil action and one being subjected to professional discipline in administrative proceedings.

Even though, most jurisdictions have found that expert witnesses should not be immune from a law suit by their clients for negligence, other courts have considered that the alleged immunity should apply in these circumstances. In the case Bruce v. Byrne-Stevens & Associates Engineers, the court ruled in favor of an expert witness sued by a client for negligently rendering opinions on damages issues in prior litigations, finding that immunity of experts would encourage them to be more careful in their performance, resulting in more reliable testimony.

Resuming, despite the fact that in the majority of jurisdictions friendly experts are not entitled to immunity for their pretrial work, immunity should apply in jurisdictions where the immunity doctrine has been silent. Thus, attorneys defending experts regarding this issue should use the argument raised in Bruce v. Byrne: “Civil liability is too blunt an instrument to achieve much of a gain in reliability in the arcane and complex calculations and judgments which expert witnesses are called upon to make. The threat of liability seems more likely to result in experts offering opinions motivated by litigants’ interests rather than professional standards and in driving all but the full-time expert out of the courtroom.”