Expert witnesses are vital to any case involving technical, scientific, or otherwise specialized knowledge. Due to their knowledge on relevant subject matter, courts will place a greater value on an expert’s testimony. This reliance on expert testimony can, however, be ruinous to an attorney’s case when an expert provides mistaken, misleading or otherwise false testimony.
Traditionally, in the United states, all witnesses were considered absolutely immune from suit for the testimony they provided in court, even if the witness made a mistake in their testimony. In fact, even if a witness’ testimony was made maliciously, with the knowledge that it was false, early court rulings suggested that an attorney could not recover damages.
Such witness immunity was considered a common-law doctrine. This principle was later reinforced by the Supreme Court in Briscoe v. LaHue, 460 U.S. (1983), in which the Court ruled that fact witnesses in criminal proceedings were immune from suit for the declarations they made in court. Over time, this idea was broadened through other court decisions to cover expert witness testimony.
The rationale behind witness immunity was twofold. Firstly, it was reasoned that witnesses might be reluctant to testify at all if there was a chance that they could be sued due to their testimony. Secondly, even if a witness decided to testify, they could repress, temper or otherwise distort their testimony if they suspected their statements could leave them open to liability.
A Change in the Tide
In recent years, however, many jurisdictions have been slowly chipping away at this doctrine. In states such as California, Connecticut, Louisiana, Massachusetts, Missouri and Pennsylvania, attorneys are now permitted to sue the “friendly” expert witnesses they have hired for breach of contract or professional malpractice. In addition, Vermont and New Jersey have ruled that court-appointed experts can be exposed to liability for negligent performance of their professional duties. The rationale for these changes is borne from the idea that the search for truth is not aided by holding experts harmless when they provide negligent or deliberately false testimony.
Further complicating the matter, Tennessee and Michigan have recently ruled in favor of upholding immunity for expert witnesses, though Michigan allows the attorney to sue their expert for any damages resulting from their reliance on the expert’s mistaken opinion. This trend has even extended to the United Kingdom, which in 2011 removed their 400-year-old witness immunity law.
While states may be split on the matter, one thing is clear: even where common-law witness immunity has been upheld, witnesses must still use a reasonable degree of care in forming their opinions and testimony.