06/13/2023 - UK Feature: The End of Expert Witness Immunity: A Landmark Supreme Court Decision

Publication Date: April 2011

In a significant ruling on March 30, 2011, the Supreme Court delivered a judgment that marked the end of more than four centuries of immunity from negligence claims for expert witnesses.

The Background

The case involved Paul Wynne Jones, who was struck by a car driven by an intoxicated, uninsured, and disqualified driver while waiting at traffic lights in March 2001. Clinical psychologist Sue Kaney was tasked with preparing a report supporting Mr. Jones' claim for damages against the driver's insurers, Fortis, in July 2003. Her initial report stated that Mr. Jones was suffering from Post Traumatic Stress Disorder (PTSD).

In December 2004, Ms. Kaney submitted a follow-up report stating that Mr. Jones exhibited some but not all of the symptoms required for a PTSD diagnosis, and also suffered from depression.

Fortis engaged a consultant psychiatrist, Dr. El-Assra, to provide a report countering Mr. Jones' claims. Dr. El-Assra contended that Mr. Jones was exaggerating his physical symptoms. At the district judge's request, both experts were instructed to produce a joint report. Dr. El-Assra prepared the report, which was signed without amendment by Ms. Kaney. The joint report downplayed the psychological impact of the accident, described Mr. Jones as deceptive and deceitful, and labeled his reaction as nothing more than an adjustment response.

Mr. Jones argued that Ms. Kaney's negligence resulted in him accepting a settlement amount significantly lower than what he would have received had she not signed the joint report.

The Legal Context

Before this judgment, expert witnesses enjoyed limited immunity against tort claims for their involvement in litigation. This immunity, which also extended to barristers and solicitors acting as advocates, was challenged in the Hall v Simons case of 2001 when the House of Lords determined that barristers' immunity could no longer be justified.

The Supreme Court Decision

In their judgments, Lords Phillips, Brown, and Dyson acknowledged the fundamental principle of the rule of law: that every wrong should have a remedy. They highlighted that the immunity granted to negligent expert witnesses denied the affected parties any recourse.

Concerns were raised that removing this immunity might discourage expert witnesses from providing evidence altogether due to potential legal liability.

However, the court concluded that such concerns were unfounded. The removal of immunity for barristers did not have a chilling effect, and there was no reason to assume that expert witnesses would fail in their duty to the court or manipulate their evidence to favor their clients out of fear of being sued. On the contrary, the court believed that experts would exercise more caution in presenting their opinions and subject them to greater scrutiny when facing the risk of litigation.

Another concern was the possibility of vexatious claims against expert witnesses by parties who had been unsuccessful in their litigation. However, the practical implications and costs associated with engaging a second expert witness to challenge the negligence of the first witness would likely deter most vexatious claims from progressing.

The court also dismissed the notion that the removal of immunity would lead to an excessive number of lawsuits.

Five out of seven Supreme Court judges supported the reasoning outlined above. Among the two dissenting judges, Lady Hale suggested that the removal of this privilege should be handled by the Law Commission or Parliament, rather than the Supreme Court. Lord Hope argued that the immunity had a long-standing precedent, and there was no compelling reason to abolish it.

The Ramifications

Expert witnesses are now advised to secure professional indemnity insurance, although many judges noted that this might already be standard practice, and the extent of coverage should be carefully reviewed.

Expert witnesses may also consider incorporating contractual terms to limit their liability,