Can an Expert Witness Be Sued? Immunity After Jones v Kaney

Yes. Since the Supreme Court's decision in Jones v Kaney [2011] UKSC 13, expert witness immunity in the UK no longer protects an expert from being sued by the client who instructed them. A surveyor who gives negligent expert evidence in England and Wales can face a claim for negligence or breach of contract like any other professional. Several important protections remain, however, and the practical risk for a competent, properly instructed RICS expert is manageable. This guide explains what changed, who can bring a claim, and how solicitors and surveyors can reduce exposure when expert witness surveyors are appointed in property disputes.

What did Jones v Kaney change about expert witness immunity?

For centuries, witnesses of all kinds enjoyed immunity from civil suit for anything said in court or in preparation for it, so that evidence could be given frankly without fear of a disappointed party suing. Expert witnesses, who are paid by one side but owe their overriding duty to the court under CPR 35.3, sat awkwardly inside that rule.

In Jones v Kaney, a clinical psychologist instructed in a personal injury claim signed a joint statement that undermined her own client's case, having apparently agreed it without proper consideration. The client sued. The expert relied on witness immunity and won at first instance, but the Supreme Court, by a five-to-two majority, abolished the immunity of expert witnesses from suit by their own clients.

The reasoning translates directly to surveying. An expert who accepts an instruction for a fee and undertakes to exercise reasonable skill and care should not be in a better position than a surveyor giving the same advice outside litigation. Removing immunity was expected to encourage more careful work, not less candid evidence, because the duty to the court already requires independence.

Who can sue an expert witness surveyor now?

The abolition of immunity is narrower than it is sometimes presented. In broad terms:

• The instructing client can sue for negligence or breach of contract if the expert's work fell below the standard of a reasonably competent expert in that discipline and caused loss. This is the change Jones v Kaney made.
• The opposing party generally cannot. An expert does not owe a duty of care to the other side, so a party who loses because the opponent's expert was persuasive, or even wrong, has no direct claim against that expert.
• Defamation immunity is untouched. Statements made in court, in a report prepared for court or in a joint statement remain absolutely privileged, so an expert cannot be sued for defamation over a critical opinion about another professional's work.

The decision applies in England and Wales; the Scottish position has not been settled in the same terms, so experts on Scottish disputes should take specific advice.

What sanctions did experts already face before 2011?

Even when immunity from civil suit applied, an expert who neglected their duties could be penalised in several ways, and all of these remain available today.

• Wasted costs orders. A court can order an expert personally to pay the costs of a party where the expert's flagrant or reckless disregard of their duties caused those costs to be wasted. The principle was established in Phillips v Symes [2004] EWHC 2330 (Ch) and is the sanction judges most often mention when criticising expert evidence.
• Contempt of court. Every expert report must carry a statement of truth in the form required by Practice Direction 35. Under CPR 32.14, proceedings for contempt may be brought against anyone who makes, or causes to be made, a false statement in a document verified by a statement of truth without an honest belief in its truth.
• Judicial criticism. A judgment describing an expert as partisan, unprepared or outside their competence is public and permanent, and for a surveyor who depends on repeat instructions from solicitors it is often the most damaging outcome of all.
• Professional discipline. RICS members are bound by the Rules of Conduct and by the RICS practice statement and guidance note Surveyors acting as expert witnesses. Failing to comply can lead to disciplinary proceedings regardless of whether any client sues.

Our guide to the RICS expert witness requirements sets out the practice statement's mandatory duties in more detail.

How much protection does an expert still have?

The protections that remain are substantial.

First, the standard of care is that of a reasonably competent expert in the relevant field, judged on the information available at the time. An opinion that turns out to be wrong is not negligent if a competent surveyor could reasonably have held it. In valuation disputes, for example, the courts accept a margin of error around any figure, so an expert whose opinion sits within the range of reasonable views is not exposed simply because the judge preferred the other side's number.

Second, a claimant must prove causation and loss. If a case would have been lost anyway, or turned on witness credibility rather than the expert's opinion, a disappointed client will struggle to show that the expert's failings caused recoverable damage.

Third, an expert who changes their view after seeing new evidence or discussing matters with the opposing expert under CPR 35.12 is doing what the court requires. Jones v Kaney did not make it negligent to concede a point; it made it actionable to concede one carelessly, without having done the work.

Fourth, written terms of engagement that define the scope of the instruction, the documents relied on and any assumptions made will frame what the client can later complain about. The RICS practice statement expects terms to be agreed in writing before work starts.

Professional indemnity insurance and expert witness work

RICS-regulated firms must hold professional indemnity insurance meeting RICS minimum requirements, and expert witness work is normally within a surveying firm's cover. Since 2011, however, surveyors have been encouraged to confirm that their policy does not exclude litigation support or expert work, and that the limit of indemnity suits the value of the disputes handled. A dilapidations or construction defects case can involve sums far above the value of a typical residential survey.

Solicitors instructing an expert can reasonably ask for confirmation of professional indemnity cover as part of the appointment. It is one of the checks in the instruction checklist for expert witness surveyors, alongside verifying discipline, experience of giving evidence and familiarity with CPR Part 35 report requirements.

Does liability change the cost of expert evidence?

Not dramatically, although the time a diligent expert spends on the file is part of what the fee pays for. Expert witness surveyors on the panel typically charge £150–£300 per hour, with straightforward property matters producing a Part 35 report for £5,000–£15,000 and complex multi-issue cases running to £20,000–£50,000 or more. Court attendance is usually £1,000–£2,000 per day. These figures reflect the work needed to produce evidence that withstands scrutiny: inspection, document review, analysis, the joint statement and answering written questions under CPR 35.6. An expert who cuts corners to quote a lower fee exposes both themselves and the client, so fee comparisons should focus on scope rather than headline price. Our expert witness cost guide explains each stage.

Where a surveyor's own work is the subject of a negligence claim, an independent expert gives evidence on the standard of care; the surveyor negligence expert witness report guide describes what that evidence covers.

Appointing an RICS expert witness through Survey Merchant

The end of blanket immunity rewards surveyors who take the duty to the court seriously. Survey Merchant provides RICS surveyors as expert witnesses for construction defects, valuation disputes, dilapidations, boundary and party wall matters across England, Wales and beyond. The panel's experts hold professional indemnity insurance, work to the RICS practice statement and CPR Part 35, and accept single joint expert as well as party appointments. Survey Merchant matches the discipline to the dispute and quotes fixed fees at the outset, so the scope is agreed in writing before work begins. To discuss an appointment, visit the expert witness services page or contact Survey Merchant on 0204 579 8270.