Supreme Court abolishes rule that expert witnesses enjoy immunity from suit
Last year, the Supreme Court in Jones v Kaney abolished the rule that expert witnesses enjoyed absolute immunity from suit. The appellant was the claimant in a PI claim arising from a road accident. The respondent was his psychiatric expert witness. In her first reports, she concluded that he was suffering from PTSD, but resiled from this position in a joint report prepared by the defence. She had failed to consider the defendant’s report properly, and had put her name to the joint report despite not agreeing with its contents. The Supreme Court held that she could be sued in negligence.
For many commentators, this decision flowed naturally from the abolition of advocates’ immunity in Hall v Simon ten years previously, and decisions such as Meadows v GMC where it was held that experts’ reports and conduct could be the subject of professional disciplinary hearings. Experts’ immunity was abolished principally on the basis that experts, unlike lay witnesses, provide their services on their own initiative for a fee. Every wrong should have a remedy where possible. This, along with their role in advising clients on matters within their expertise, makes expert witnesses akin to other professional advisors whose clients were able to sue.
So far, the only reported case following this decision is Ridgeland Properties v Bristol City Council  EWCA Civ 649. There, the appellant property company appealed an Upper Tribunal (Lands Chamber) decision determining the amount of compensation due following a compulsory purchase order. Their surveyor had omitted relevant information from his report and subsequent testimony. That the appellant now had a potential remedy in negligence against the surveyor influenced the Court of Appeal in dismissing their bid to re-open the Lands Chamber proceedings.
Litigation will take some time to reach the appellate courts, so it is unsurprising that we haven’t yet seen a flurry of reported decisions on this subject. The scope of the decision is yet to be wholly clarified, and it is uncertain whether Lord Phillips’ leading judgment applies beyond cases where the expert has changed his mind in the course of litigation. Experts’ overriding duty to assist the court remains unaffected by this ruling, but the extent of an expert’s duty to his lay client, and the way it co-exists with experts’ overriding duty to assist the court under CPR Part 35 is not wholly clear. It cannot be the case that any expert who modifies his position in the light of discussion with the other side breaches his duty to the lay client, but it will take some further judicial refinement before we can benefit from a reliable test of whether an expert has acted negligently.
The Court’s majority seemed to dismiss the possibility that their ruling might deter experts from giving evidence or otherwise affect how they act. The practical consequences of this decision will inevitably include a number of claims against experts by disappointed litigants, some well-founded and others more speculative. It might also have the unfortunate consequence of driving up experts’ fees further, as they pass on the cost of additional insurance, and also perhaps of making individual experts more risk-averse in marginal cases.