House of Lords abolishes 400 year old rule of law

Posted on

Expert witnesses lose immunity from suit


Supreme Court Law Report 31st March 2011

London, England


Jones V. Kaney


Before Lord Phillips of Worth Matravers, Lord Hope of Craighead, Baroness Hale of Richmond, Lord Brown of Eaton – under – Heywood, Lord Collins of Mapesbury, Lord Kerr of Tonaghmore and Lord Dyson. Judgement 30th march 2011.

The 400 year old rule that immunity from suit for breach of duty that expert witnesses had enjoyed in relation to their participation in legal proceedings should be abolished.


There was no justification for continuing to hold expert witnesses immune from suit in negligence in relation to the evidence they gave in court or for the views they expressed in anticipation of court proceedings.

The Supreme Court so held by a majority, Lord Hope and Lady Hale dissenting, in allowing an appeal by the claimant, Paul Wynne Jones, from Justice Blake ([ 2010]EWHC 61 (QB) who struck out his claim for negligence against the defendant, Sue Kaney, a clinical psychologist, in respect of her preparation of a joint experts’ action brought by Mr Jones following a road traffic action.

Lord Phillips said that in Stanton v Callaghan (The Times 25th July 1998 : [1998] QB 75) the Court of Appeal held that the immunity of an expert witness extended to protect him from liability for negligence in preparing a joint statement for use in legal proceedings.  

The claim in the present case related precisely to such negligence and was, for that reason struck out.

The judge, however, granted a leapfrog certificate under Section 12 of the Administration of Justice Act 1969.

Surprisingly, the immunity conferred on an expert witness from liability in negligence in relation to performance of his duties in that capacity had never been challenged in the past. It had simply been accepted that an immunity which protected witnesses of fact applied equally to prevent a client from suing in negligence the expert that he had retained.

The immunity of expert witnesses had a long history, dating back over 400 years. Thus the immunity was established long before the development of the modern law of negligence and long before it became common for forensic experts to offer their services under contracts for reward.

However, there was no reported case where immunity was invoked against a claim for breach of a duty of care brought against a professional expert witness by his client before Palmer v Durnford (The Times 11th November, 1991;[1992]QB 483), which applied by analogy the decision in relation to the advocate’s immunity  from suit in Saif Ali v Sydney Mitchell & Co (The Times 3rd November, 1978;[1980] AC 198).

In Arthur J.S. Hall & Co v Simons (The Times 21st July, 2000;[2002] 1 AC 615) the House of Lords abolished immunity from liability in negligence in the case of barristers, without questioning the immunity of experts.

 Was the experts’ immunity justified? The general principle was that no wrong should be without a remedy.

Accordingly, the issue was whether the abolition of immunity would probably be attended by such disadvantage to the public interest as to make its retention clearly justifiable.

His Lordship could see no justification for the assumption that, if expert witnesses were liable to be sued for breach of duty, they would be discouraged from providing their services at all. Why should the risk of being sued in relation to forensic services constitute a greater disincentive to the provision of such services than did the risk of being sued in relation to any other form of professional service? The principal justification for immunity that the defendant urged was that it was necessary to ensure that the expert performed his duty to the court.

That duty required him, whether when attempting to reach agreement with the expert on the other side, or when giving evidence to the court, to give his honest opinion, even if that proved adverse to his client’s case.

The defendant submitted that the expert would have some apprehension about taking such a course and that immunity from suit was necessary to allay that apprehension.

However, as expert witnesses had, to date, had the benefit of immunity, how they would behave if that immunity was removed had to be a matter of conjecture or, more accurately, reasoned. But if reasoning was applied, it did not support the defendant’s thesis.

An expert’s initial advice was likely to be for the benefit of his client alone. It was on the basis of that advice that the client was likely to decide whether to proceed with his claim, or the terms on which to settle it.

If the expert subsequently formed the view, or was persuaded, that his initial advice was over optimistic, or  that there was some weakness in his client’s case which he had not appreciated, his duty to the court was frankly to concede his change of view.

The witness of integrity would do so.

It was possible that some experts might not have that integrity. They might be reluctant to admit to the weakness in their client’s case because of loyalty to the client and his team, or because of a disinclination to admit to having erred in the initial opinion.

His Lordship questioned, however, whether their reluctance would be because of a fear of being sued; at least a fear of being sued for the opinion given to the court. An expert would be well aware of his duty to the court and that if he frankly accepted that he had changed his view, it would be apparent that he was performing that duty.

There was a lesson to be learnt from the position of barristers. It was always believed that it was necessary that barristers should be immune from suit in order to ensure that they were not inhibited from performing their duty to the court. Yet removal of their immunity had not resulted in any diminution of the advocate’s readiness to perform that duty.

His Lordship also doubted whether the removal of expert witness immunity would lead to a proliferation of vexatious claims or a risk of multiplicity of suits. Accordingly, no justification had been shown to continuing to hold expert witnesses immune from suit in relation to the evidence they gave in court or for the views they expressed in anticipation of court proceedings.

It follows that the immunity from suit for breach of duty that expert witnesses had enjoyed in relation to their participation in legal proceedings should be abolished.

His Lordship emphasised that that conclusion did not extend to the absolute privilege that they enjoyed in respect of claims in defamation.


Lord Brown, Lord Collins, Lord Kerr and Lord Dyson delivered concurring judgments.

Lord Hope, dissenting, said that the lack of a secure principled basis for removing immunity, the lack of a clear dividing line between what was to be affected by the removal and what was not, the uncertainties that would cause and the lack of reliable evidence to indicate what the effects might be suggested that the wiser course would be to leave matters as they stood.

If there was a need to reform the law in this area, it would be better dealt with by Parliament following the report by the Law Commission.

Lady Hale  also delivered a dissenting judgment.