Supreme Court abolishes immunity from suit for expert witnesses

Jones v Kaney [2011] UKSC 13

In January this year the Supreme Court overturned 400 years of legal practice by abolishing the immunity from suit enjoyed by expert witnesses in relation to their participation in legal proceedings. In an appeal heard under the leapfrog procedure[1] the SC, by a majority of 5-2, held that there was no longer any justification for retaining the rule. Experts who act without reasonable care and skill or who are negligent in the preparation of their opinions or advice will now be open to claims for damages.

The traditional view

The immunity of expert witnesses can be traced back to 1585 and the case of Cutler v Dixon[2]. It predates the development of the modern law of negligence and also the practice of experts providing their services under contract for payment. Its origins lie in the fear that disgruntled litigants would bring proceedings for libel or slander against those giving evidence against them and originally took the form of an absolute privilege against a claim for defamation. It later extended to other forms of action in tort, the concern being that, without immunity, witnesses would be reluctant to testify, or at least to testify freely and openly, for fear of vexatious claims being brought against them. This justification for the immunity was noted by the House of Lords as recently as 2001[3], although others have also been commonly raised.

The leading authority on expert immunity, until now at least, was the 1998 case of Stanton v Callaghan[4]. In that case, the facts of which echo Jones v Kaney, an expert surveyor was sued by his own client for his part in the preparation of a joint expert report which differed considerably from the opinion the surveyor had first expressed to the claimant, leading to a settlement of the case for only a quarter of the figure first suggested. The claim against the surveyor was struck out, the Court of Appeal noting that the law recognised witness immunity from suit in relation to certain things done in preparing for, or taking part in, a trial on the basis of a supervening public interest of ensuring the proper conduct of the trial, and that the public interest required experts to be able to discuss their opinions freely without fear that any change from previous advice given would be indicative of negligence. This was so whether the opinions and report were later used in a trial or, because the dispute settled before trial, were not.

Jones v Kaney - the facts

The claimant, a Mr Jones, had been injured in a road traffic accident when he was hit by an uninsured driver, resulting in him suffering serious physical and psychological injuries. His solicitors retained the defendant clinical psychologist, Dr Kaney, who examined the claimant and reported that he was suffering from post traumatic stress disorder. Proceedings were issued against the driver and Motor Insurance Bureau (now known as Fortis) who admitted liability, leaving only the question of quantum to be determined. Their expert considered that Mr Jones was exaggerating his medical symptoms and, as instructed by the trial court, the two experts held a telephone meeting to agree a joint expert report. The report did not accurately record what had been discussed on the telephone, nor did it accurately reflect Dr Kaney’s views but she signed it nonetheless. It was very damaging to the claimant’s case and, as a result, his solicitors advised him to settle for a sum considerably less than he could had hoped for had he won at trial. He sued Dr Kaney for negligence.

At first instance, the judge found he was bound by the Court of Appeal decision in Stanton v Callaghan and was obliged to strike out the claim. However, he certified the case as one suitable for a leap-frog appeal to the Supreme Court.

The Supreme Court decision

The majority of their Lordships, led by Lord Phillips, found that there was no longer any justification for retaining the immunity rule. They considered a number of arguments which had previously been advanced for retaining the rule, but found them wanting. They did not accept that removing immunity would discourage experts from acting as such, or from giving full and frank evidence when that conflicts with their clients’ interests, for fear of civil action (the “chilling effect”). It is apparent that the Lords were influenced in their reasoning by the removal of immunity from suit for advocates resulting from the case of Arthur JS Hall & Co v Simons[5] in 2000. Since that case, barristers have been open to claims from former clients who allege they have suffered loss as a result of their barrister’s breach of duty, whether tortious or contractual. The Court noted that there had not been a great decrease in the number of barristers willing to act since their immunity was abolished. Nor did the Court accept that there was likely to be a flood of claims brought by unsuccessful claimants against their experts. Again, the experience of barristers suggests that this is unlikely to happen. It remains difficult to bring an action for negligence against an expert requiring, as it does, the opinion of another expert at yet more expense. Claims which are clearly vexatious would be struck out in any event. Lord Brown suggested that in fact, there could be a resultant increase in the care taken by experts in the preparation of their reports so as not to put a case too high or inflexibly so that it comes back to embarrass them at a later stage.

Reference was also made to the decision in 2006 to remove immunity for experts from disciplinary proceedings by a professional body relating to the preparation or giving of expert evidence. In the Court’s view, the potential effects of a sanction from a professional body are more serious than civil proceedings, but the removal of immunity in such cases has not led to any great reluctance on the part of experts to testify.

Lord Dyson noted that experts owe a duty to the court which overrides that to their client and does not conflict with it. An expert’s duty to his client will include both the duty to act with reasonable care and skill, and to act in accordance with his overriding duty to assist the court. Discharging his duty to the court cannot be a breach of his duty to his client unless he acts outside the range of reasonable expert opinions.

The longevity of the principle was also dismissed by the majority of the Court as a factor mitigating against its abolition. In Lord Dyson’s words, “the mere fact that the immunity is long-established is not a sufficient reason for blessing it with eternal life.” The underlying principle of justice is that for every wrong there should be a remedy, and exceptions to that rule must be justifiable by public policy. However, he added, public policy can change and exceptions should be kept under review to ensure there is still a compelling reason for maintaining the rule.

The dissenting Justices, Lord Hope and Lady Hale, were not so certain that witnesses would not be deterred from giving evidence were they to be open to civil claims. They considered that the principle would be better removed by Parliament.

Practical implications

  • Expert witnesses will now no longer be protected against claims from their clients for professional negligence arising from their opinions or evidence.
  • An expert who gives an independent and unbiased opinion, within the range of reasonable expert opinions, will have discharged his duty to both his client and the court. He will not be liable merely because his opinion is unhelpful to his client’s case.
  • It is unlikely that the flood gates will be opened and we will see a large number of cases being brought against experts by their disgruntled clients. Successful cases against expert witnesses are still likely to be rare, for reasons both of finance and proof.
  • Experts may take increased care when giving their initial opinions, or be more reluctant to give strong unqualified evidence. Whether they are deterred from acting altogether remains to be seen.
  • The cost of professional indemnity insurance for expert witnesses may conceivably increase. These costs may be passed onto the expert’s clients.
  • Experts may wish to negotiate more robust limitation or exclusion of liability clauses in their terms of engagement.
  • Where a joint report is being prepared, experts should ensure they are satisfied that it fully and fairly reflects the views of each of them, and that the clients have been consulted, before it is finalised. 
  • All witnesses, including experts will continue to enjoy privilege from suit for defamation claims, which is untouched by this decision.


It came as no surprise to anyone familiar with this area of practice that the Supreme Court should decide to abolish immunity from suit for experts. However, the two dissenting Justices raised concerns which should not be overlooked. They regretted the absence of any intervention in the appeal by a body such as the Academy of Experts, who could have provided the Court with evidence of the likely impact of removing immunity from experts rather than the Court having to infer what would be the result. They did not consider that a secure principled basis for abolishing immunity had been made out, and pointed to the uncertainties caused by the lack of a clear dividing line between what is to be affected by the principle’s removal and what is not. Lady Hale was particularly concerned at the lack of delineation of the principle and listed a number of other types of proceedings that might now be affected, adversely, such as private law proceedings in tribunals, landlord and tenant in leasehold valuations, employment cases, local authority matters and ancillary family cases. Indeed, she termed the making of such a change on such an uncertain basis, “irresponsible”. How far the withdrawal of immunity will extend and into what other areas of civil litigation, together with the practical effect the abolition of immunity for expert witnesses will have, only time will tell.

[1]    Section 12 Administration of Justice Act 1969
[2]    (1585) 4 Co Rep 14b
[3]    Darker v Chief Constable of the West Midlands Police [2001] AC 435
[4]    [2000] QB 75
[5]    [2002] 1AC 615