Replacing Expert Witnesses: Expert shopping or genuine concern?

A recent application to the High Court to replace two experts with one new expert has been considered by Mrs Justice O’Farrell DBE and provides useful insight to legal teams regarding when permission to change an expert witness will be granted and the documentation ordered to be disclosed.

The case relates to a fire at a retirement village in 2019 which almost destroyed the entire property, and the claimants seeking damages of over £40m in respect of alleged deficiencies in design and the construction of the property.

In this application, the claimants sought to replace two experts; one a Forensic Scientist, the other a Fire Engineer.

The court’s power to change an Expert Witness

In the judgment, Mrs Justice O’Farrell provides a useful summary of the relevant principles and discretionary powers the court has as was considered in the case of The University of Manchester v John McAslan & Partner and others [2022] EWHC 2750 (TCC):

i) The court has a general discretion to permit a party to change the identity of the expert on which it relies, pursuant to its specific power to control the use of expert evidence under CPR 35.4 or as part of its general case management powers under CPR 3.1(2).

ii) Such general discretion should be exercised having regard to all the material circumstances of the case and in accordance with the overriding objective.

iii) The usual rule is that the court should not refuse a party permission to rely on a new expert in substitution for an existing expert: Edwards-Tubb v JD Wetherspoon plc [2011] EWCA Civ 136 per Hughes LJ at [30]; Murray v Devenish [2017] EWCA Civ 1016 per Gross LJ at [15]-[16].

iv) Where a party requires the court's permission to rely on a new expert in substitution for an existing expert, the court has the power to give permission on condition that the original expert's reports, containing the substance of the expert's opinion, are disclosed to the other parties and such condition will usually be imposed: Beck v Ministry of Defence [2003] EWCA Civ 1043 per Simon Brown LJ at [24]-[26]; Vasiliou v Hajigeorgiou [2005] EWCA Civ 236 per Dyson LJ at [29]-[30].

v) The justification for imposing a condition that the original expert's reports should be disclosed includes (a) prevention of expert shopping and (b) ensuring that the expert's contribution is available to the court and all parties, regardless of the instructing party: Vasiliou (above) at [29]; Edwards-Tubb (above) at [30].

vi) The court's power to impose a condition on the grant of permission to change an expert may extend to other documents containing the substance of the original expert's opinion but the court must be cautious about encroaching upon areas of privilege and consider carefully the potential value of such other documents; in particular, there must be a strong case to justify disclosure of solicitors' attendance notes: BMG (Mansfield) Ltd v Galliford Try Construction Ltd [2013] EWHC 3183 (TCC) per Edwards-Stuart J at [28]-[32].

Changing the Forensic Scientist

The application to change the Forensic Scientist had not been opposed in principle by the Defendants. The Expert Witness has a serious illness which requires treatment and prevents her from continuing to participate in the proceedings. However, their position was that her earlier reports, opinions and investigation notes be disclosed.

Considering submissions from each side that on the basis that this was clearly not a case of expert shopping and a case of necessity due to the expert’s illness, there would usually be no reason to disclose all reports or other documents setting out her opinion.

However, because the Expert had played such a significant part in the litigation; leading an investigation at the property before it was demolished, interviewing a resident, and providing substantial input into the statements of the case, Mrs Justice O’Farrell stated that the court would order the disclosure of all reports and notes.

The reasons for this are:

• The expert’s documentation contained evidence of primary facts that would now be unavailable through any future inspection due to demolition of the property.

• If she had continued to act in the case, it is likely she would have referred to the documents and there would have therefore been a requirement to disclose them anyway.

• It is likely the replacement expert will be given access to the documents.

• In the interest of fairness and transparency, one of the defendant’s had not been involved in the dispute in the early stages and therefore their expert did not participate in early investigations.

• Notes of the interview with the resident may include relevant information that would not have been included in their witness statement.

Changing the Fire Engineer

The grounds for changing the Fire Engineer were less clear and the defendants opposed the application because the expert to be replaced is qualified and available to give expert evidence at trial.

The reasons put forward by the Claimants across two witness statements include:

• The expert had relied on a colleague to carry out analysis with respect to sprinkler capability but was not a fire engineer. However, the Forensic Scientist had been able to cover this. And as this expert was being replaced, they wished to change the Fire Engineer.

• The considerable overlap of evidence from the Forensic Expert and the Fire Engineer.

• Concern that there was a conflict of interest from the Fire Engineer.

• The claimants do not have confidence in the Fire Engineer.

• The claimants accept that the three reports prepared by their Fire Engineer would be disclosed.

Whilst noting the legitimate concerns from the defendants, Mrs Justice O’Farrell granted the application to change the Expert Witness stating that:

“It is in the interests of justice that the claimants should have permission to rely on an expert in whom they have confidence.”

She ordered that the expert’s reports, draft reports, and any further documents in which the expert had expressed an opinion to be disclosed.

Learning points:

1. If the grounds for changing your expert are clear cut (such as illness) the court may still order the disclosure of documents if they contain information or evidence of primary facts that should be made available to all.
2. The court will accept lack of confidence in the expert as grounds for a change, but you will need to be clear of the reasons and be aware that all opinion provided by that expert will be disclosed.
3. If you are seeking to change your expert, provide as much clarity as possible regarding the reasons for the change.