Supreme Court decision

The Supreme Court has swept away the longstanding immunity from suit afforded to expert witnesses in a five-to-two majority decision in Jones v Kaney.(1) The decision had been widely expected, given that advocates' immunity was removed in 2001.


Mr Jones was the victim of a road traffic accident. He was knocked off his motorcycle by a car driven by a drunk, uninsured and disqualified driver. Jones suffered significant physical and psychiatric injury as a result.

Jones consulted solicitors, who brought a claim for personal injury on his behalf. Unsurprisingly, liability was admitted by the insurers, but quantum remained in issue. Jones's solicitors instructed Dr Kaney, an expert clinical psychologist, to examine their client and prepare a report for the litigation. Kaney concluded that Jones was suffering from post-traumatic stress disorder. The court ordered the parties' experts to hold discussions and to prepare a joint statement. The discussion took place by telephone and Kaney signed the draft joint statement that the opposing expert had prepared, without amendment or comment.

The joint statement was damaging to Jones's claim: it recorded an agreement that Jones had not suffered from post-traumatic stress disorder and had been deceitful in his reporting. When asked to explain the discrepancy between the joint report and her earlier assessments, Kaney provided what the first instance judge described as "an unhappy picture" of how the joint statement came to be signed.

Jones then pursued a claim against Kaney, alleging that as a result of her report, he had been obliged to settle his claim for significantly less than he would otherwise have obtained. Kaney applied to have the claim against her struck out on the basis that expert witnesses have immunity from suit. The judge at first instance had no option but to grant that application, as he was bound by prior Court of Appeal authority on the issue. However, he also gave Jones permission to appeal directly to the Supreme Court.

Supreme Court decision

The Supreme Court reviewed the history and development of expert immunity and the reasons for it. Lord Phillips, who gave the leading judgment, explained that the history of expert immunity dates back over 400 years. The continuous theme running through the cases was:

"the chilling effect that the risk of claims arising out of conduct in relation to legal proceedings would have. It would make claimants reluctant to resort to litigation. It would make witnesses reluctant to testify. If they did testify, it would make them reluctant to do so freely and frankly. The cases emphasise that the object of the immunity is not to protect those whose conduct is open to criticism, but those who would be subject to unjustified and vexatious claims by disgruntled litigants."

The leading case on expert immunity was Stanton v Callaghan.(2) In that case, the Court of Appeal held that expert witnesses should have absolute immunity from suit for claims relating to the evidence that they give in court, and that such immunity would extend to the contents of the report that the expert adopts as his or her evidence.

Lord Justice Chadwick explained that:

"In my view, the public interest in facilitating full and frank discussion between experts before trial does require that each should be free to make proper concessions without fear that any departure from advice previously given to the party who has retained him will be seen as evidence of negligence. That, as it seems to me, is an area in which public policy justifies immunity. The immunity is needed in order to avoid the tension between a desire to assist the court and fear of the consequences of a departure from previous advice."

The court drew an analogy between the position of an expert witness and that of an advocate, and applied the reasoning of the House of Lords in Rondel v Worsley(3) in which it was held that barristers needed to be afforded immunity from suit in order to be given the fullest opportunity to discharge their duties to the court.

In Arthur JS Hall v Simons(4) the House of Lords abolished the principle of immunity from liability in negligence for barristers. However, immunity for expert witnesses remained intact.

Against this background, the leading judgment reviewed the purposes of expert immunity and considered whether it could be justified. It was found that the primary purposes of expert immunity were to address:

  • the reluctance that an expert would have to give evidence that was contrary to his or her client's interest, if there was a risk that this might lead the client to sue the expert;
  • the risk that potential liability in negligence would make expert witnesses more reluctant to provide their services; and
  • the undesirability of a court being required to pass judgment on the correctness of the decision of another court, which is a possible consequence of permitting claims for negligence against expert witnesses.

Is immunity justified?
The leading judgment stated that it would be wrong to start with a presumption that because immunity exists, it should be maintained unless it is shown to be unjustified. Rather, the onus lay on Kaney "to justify the immunity behind which she [sought] to shelter". The judgment went on to consider the various justifications advanced for the immunity.

Reluctance to testify
No justification was found for the assumption that if expert witnesses were to lose their immunity, they would be discouraged from offering their services. All who provide professional services which involve a duty of care are at risk of being sued for breach of that duty, and customarily insure against this risk.

Ensuring that experts give full and frank evidence
There was no empirical evidence to support the assertion on this point. It was felt that as experts have had the benefit of immunity to date, their behaviour if immunity were to be removed was a matter of conjecture or reasoning. If an expert is reluctant to admit to a change of mind when giving evidence in court, that might be because of loyalty to the client or his or her team, or because of a disinclination to admit to having been wrong in an earlier opinion. It was questioned whether reluctance would be due to a fear of being sued for the opinion given in court. The removal of barristers' immunity had not made advocates less willing to perform their duty to the court.

Potential for vexatious claims for breach of duty
This case was not an example of a vexatious claim, but the leading judgment expressed doubt as to whether the removal of immunity would lead to a proliferation of vexatious claims - if only because getting such a claim off the ground would require the support of another expert.

Risk of multiplicity of suits
This argument was dismissed, although it was conceded that the risk of such claims was greater from those convicted of a criminal offence.

It was concluded that there was no real justification for continuing to hold expert witnesses immune from suit in relation to the views that they give in court or express in anticipation of court proceedings.

Concurring views
Lords Kerr and Dyson agreed, as did Lord Brown, who said that he would welcome the most likely consequence of removing immunity from experts, which would be "a sharpened awareness of the risks of pitching their initial views of the merits of their client's case too high or too inflexibly, lest these views come to expose and embarrass them at a later date".

He also thought that in the rare cases where the expert behaves in an "egregious" manner or negligently causes his or her client loss, the wronged client should have a proper remedy.

Lord Collins also agreed, and held that:

"[the] practical reality is that if the removal of immunity would have any effect at all on the process of preparation and presentation of expert evidence (which is not in any event likely), it would tend to ensure a greater degree of care in the preparation of the initial report or the joint report."

Dissenting judgments
Lord Hope and Lady Hale dissented. Both disagreed with the approach taken by the majority of reviewing the justification for immunity. The rule was longstanding and they considered that the correct approach was to decide whether an exception to that rule could be justified in the circumstances of this case. They thought that reform of the law on immunity in general was better left to Parliament.


The vast majority of experts are undoubtedly highly professional in their approach to the giving of opinions and advice. However, the removal of expert immunity highlights the need for experts to ensure that they:

  • are entirely comfortable with the opinions they give;
  • are alive to the risk of adapting or altering their opinions under pressure from the client or its legal representatives; and
  • they take particular care when they meet an opposing expert and agree a joint report.

In meeting an opposing expert and agreeing a joint report, it is vital for experts to explain fully to their clients the reasons for any proposed departure from an earlier opinion before signing a joint experts' statement or making concessions on their client's behalf.

In future, parties may find that their experts' views and opinions are less bullish and more caveated. Although this might be frustrating at the time, it may have the effect of promoting more accurate and flexible experts' reports - on both sides of the litigation - and encouraging less entrenched positions, potentially making disputes easier and quicker to resolve.

For further information on this topic please contact Alexandra Anderson at Reynolds Porter Chamberlain LLP by telephone (+44 20 3060 6000), fax (+44 20 3060 7000) or email ([email protected]).


(1) [2011] UKSC 13.

(2) [2000] QB 75.

(3) [1969] 1 AC 191.

(4) [2002] 1 AC 615.