Expert witnesses are no longer immune from liability in negligence for breaches of duty owed to clients, as public policy does not justify such immunity.

Introduction

[1]"A feature of the trial is that in the public interest all those directly taking part are given civil immunity for their participation....Thus the court, judge and jury, and the witnesses including expert witnesses are granted civil immunity. This is not just privilege for the purposes of the law of defamation but is a true immunity" - Arthur JS Hall & Co v. Simons [2002] 1 AC 615, 740, per Lord Hobhouse of Woodborough. In Stanton v. Callaghan [2000] 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 pursuant to RSC, O 38, r 38. The claim in this case relates precisely to such negligence and was, for that reason, struck out by Blake J on 22 January 2010. He certified, however, that the case involved a point of law of general public importance and granted a "leapfrog certificate" under s 12 of the Administration of Justice Act 1969, so that this appeal is brought directly from his decision.

[2] The narrow issue raised by this appeal is whether the act of preparing a joint witness statement is one in respect of which an expert witness enjoys immunity from suit. Mr Ter Haar QC for the appellant was careful to emphasise at the outset of his submissions that he was not concerned to do more than establish that an expert witness enjoyed no immunity in relation to this activity. Inevitably, however, his submissions have raised the broader issue of whether public policy justifies conferring on an expert witness any immunity from liability in negligence in relation to the performance of his duties in that capacity. Surprisingly, this immunity has never been challenged in the past. It has simply been accepted that an immunity which protects witnesses of fact applies equally to prevent a client from suing in negligence the expert that he has retained.

The Facts

[3] In so far as this statement of the facts describes conduct on the part of the respondent, the facts are not proved but asserted in the particulars of claim. They are to be treated as true for the purpose of resolving the question of whether this claim was properly struck out. Understandably, the respondent has not suggested that the facts asserted do not disclose a good cause of action if she is susceptible to liability in negligence.

[4] The action has its origin in a road traffic accident that occurred in Liverpool on 14 March 2001. The appellant was stationary on his motorcycle, waiting to turn at a road junction, when he was knocked down by a car driven by a Mr Bennett. Mr Bennett was drunk, he was uninsured and he was driving while disqualified.

[5] The appellant suffered significant physical injuries, but these were not of such severity as to dwarf the significance of the psychiatric consequences of his accident. These were post traumatic stress disorder (PTSD), depression, an adjustment disorder and associated illness behaviour which manifested itself in chronic pain syndrome.

[6] On 20 March 2001 the appellant instructed solicitors ("Kirwans") to act for him in personal injury proceedings. Kirwans instructed a consultant orthopaedic surgeon who advised that an opinion from a clinical psychologist would be of help. The respondent is a consultant clinical p