UK: Expert Witness Immunity Removed

Last Updated: 5 April 2011
Article by Simon Chandler and Giles Tagg

As anticipated in our previous Law Now click here the Supreme Court in Jones -v- Kaney has abolished the principle of expert witness immunity from suit in relation to evidence given in civil proceedings.  This was a 5 to 2 majority decision handed down on 30 March 2011.  The ruling is significant for those who undertake work as expert witnesses, who may now be sued by their clients for breaches of duty committed in the course of all work that they undertake.  Previously, the immunity protected experts in relation to work undertaken in proximity to court hearings.  The practical impact of the decision remains to be seen.  It is certainly likely to lead to upward pressure on professional indemnity premiums for expert work.  Whether it will lead to a surge in satellite litigation when disappointed litigants turn to their former experts to recoup losses is a matter of speculation.  We predict that such cases will be relatively rare.  We also consider that the discouragement of underperforming experts is a welcome development.


A consultant clinical psychologist was retained to act as an expert witness for the claimant in a personal injuries claim.  Following a telephone discussion between the experts in the case, the claimant's expert signed a joint statement prepared by the opposing expert, without making any comment or amendment.  She later said that the joint statement did not reflect what she had agreed in the telephone discussion but that she had felt 'under pressure' to sign it.  As a result of the damaging nature of admissions in the joint statement, the claim was settled for a sum that was considerably less than would have been the case if the claimant's expert had not signed the joint statement in the terms that she did.

The claimant brought proceedings against the expert.  The expert relied upon the principle that an expert witness in civil proceedings is immune from being sued.  At first instance the expert was successful and the claim was struck out.  The issue came before the Supreme Court as a result of a 'leap-frog' certificate enabling the claimant to bypass the Court of Appeal in its appeal against the strike out decision based upon the immunity rule.

Supreme Court Decision

Lord Phillips' leading judgement framed the key question to be addressed as follows: does public policy justify holding an expert witness immune from liability in negligence in relation to the performance of his duties in that capacity?  The onus was on the expert to justify the immunity behind which she sought to shelter and Lord Phillips decided that justification was not made out.  In a neatly segmented judgement, Lord Phillips examined (amongst other things) the purposes of the immunity, its scope and whether it is justified.  Central to his decision were the following considerations:

  • A key argument raised by the expert was that removal of the immunity would have a  "chilling effect" on expert witness work, rendering experts more reluctant to provide their  services and fearful of giving evidence contrary to their clients interests.  This argument was  dismissed.  It was deemed paradoxical to state that in order to persuade an expert to perform  his duty to his client it is necessary to grant immunity from liability for breach of that duty.  It  was also observed that the removal of immunity from barristers (Hall v Simons 2000) had had no  such "chilling effect" on that profession.
  • The expert also raised the risk of numerous vexatious claims against experts by their former  clients whose expectations in the litigation were not met.  This argument was also afforded little  weight, in part  because such claims would not be viable without the support of another expert  witness, who would need to declare that the expert in question expressed views that could not be  reasonably held within that profession (ie: the Bolam test).
  • It was considered that removal of the immunity was unlikely to deter the expert from giving full  and frank evidence.  If an expert expresses a view honestly held, even if it differs from the view  originally expressed, he has nothing to fear from a disgruntled client provided the opinion is  tenable and soundly based.

Therefore, there were no compelling public policy reasons to support the upholding of the immunity. 


The decision may, for obvious reasons, lead to a measure of disquiet amongst those professionals carrying out expert witness work.  Previously they could not be sued for evidence given in civil proceedings; now they can be. 

Most expert witnesses will already benefit from cover under their company's PI cover.  We expect that many Insurers will want to introduce (if not already featuring) a question in proposal forms for such PI cover, asking whether expert work is undertaken within the company and in what proportion. 

Other expert witnesses, operating on an individual basis and not working for a company, will need to consider procuring bespoke PI insurance for expert witness work, if they do not already have it. 

Experts are likely to respond to this development by seeking to agree contractual limits to their exposure derived from expert assignments, in the same way that accountants and larger law firms do so for significant projects. There is no reason why such a mechanism should not succeed and work to control an expert's exposure provided it takes into account the various factors prescribed in the UCTA 1977.

It is likely that premiums will rise to reflect additional risk.  However, in our view, there is unlikely to be a sudden swathe of claims against expert witnesses.  We say that primarily because, if an expert's expressed view is reasonable, he has nothing to fear.  Finally, we welcome the fact that this decision ought to discourage enterprising but insufficiently adept expert witnesses from undertaking the work in the first place.

Further reading: Jones v Kaney [2011] UKSC 13 click here

Hall v Simons [2000] UKHL 38 click here

This article was written for Law-Now, CMS Cameron McKenna's free online information service. To register for Law-Now, please go to

Law-Now information is for general purposes and guidance only. The information and opinions expressed in all Law-Now articles are not necessarily comprehensive and do not purport to give professional or legal advice. All Law-Now information relates to circumstances prevailing at the date of its original publication and may not have been updated to reflect subsequent developments.

The original publication date for this article was 31/03/2011

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