It is a fundamental principle of the English legal system that experts should be independent and that their obligations are to the Court, not to act as advocates for their instructing solicitors, or the paying client.

The recent case of Patricia Andrews & Ors v Kronospan Limited [2022] EWHC, shows the risks to a Claimant where an expert, and/ or instructing solicitors, overlook this overriding principle. 


The claim concerned a group action brought by Claimants who alleged that the Defendant was liable to them in nuisance caused by the dust, noise and odour emissions emitted from its wood processing plant. Liability was denied.

At the first CMC on 15 May 2018, permission was given for each party to rely upon the evidence of an expert in dust dispersion modelling. An order dated 7 December 2018 gave permission for each party to have expert evidence in a further discipline, dust analysis and monitoring. The Claimant decided to rely on a single expert with experience in both disciplines.

An issue for both experts in dust analysis is the very technical nature of the specialism, and as such there has been very little agreement or common approach on any issue between the parties’ appointed experts. Consequently an Order dated 25 March 2019 stated that:

“In order to ensure that the parties experts are reporting on the same basis, the experts are to continue discussions to agree between them, and identify areas where they have not agreed, their approach, and they are to prepare and file with the court a document in respect of each report.”

The dust analysis reports were eventually exchanged in April 2021, and joint discussions commenced in May 2021.

On 24 December 2021, it came to light that there had been frequent communication between the Claimant’s solicitor and their expert during the period of joint statement discussions. These communications lasted from early May 2021 - 18 November 2021 and included working drafts being passed between the Claimant’s solicitors and their expert along with frequent and telephone discussions where the content of the joint statement was discussed. Consequently, the Defendant brought an application to revoke the Claimant’s permission to rely on their expert.

The Claimant’s expert had incurred fees of £225,000 and had been involved with the claim for over 3 years.

The Hearing

The Defendant contended that, although drastic, revoking the Claimant’s right to rely on their expert’s evidence was the only sanction available. In discussing the contents of the joint statement the expert had proven themselves to be an advocate for the Claimant and could therefore not be truly independent. His conduct, and that of the Claimants’ solicitors amounted to a failure to comply with the terms upon which the Claimants were given permission to adduce their expert evidence and were a clear breach of CPR 35 and 35PD.9, which specifically states that legal representatives should not attend expert discussions

The Claimants solicitors responded by acknowledging that their conduct was inappropriate, accepting that they had made at least 16 comments relating to “advice and suggestions as to content”. Nevertheless the Claimant’s sought to rely on the decision in BDW Trading Ltd v Integral Geotechnique (Wales) Ltd [2018] EWHC 1915(TCC) stating that such an order would be:

“Entirely disproportionate… and potentially disastrous for the 159 households who bring this claim. The proceedings have been on foot since 2017, [our expert] has been involved for over 3 years and revocation of [our expert’s] right to give evidence will cause significant additional costs for the Claimants."


Senior Master Fontaine stated that the Claimant’s actions constituted a “serious transgression of CPR 35PD paragraph 9” and that it was inappropriate for independent experts to seek input from their client's solicitors into the substantive content of their joint statement.

Given the gravity of these transgressions, which occurred on numerous occasions over a period of many months Senior Master Fontaine concluded that it was appropriate, and not disproportionate, to revoke the Claimant’s permission to rely on their experts evidence. This decision was made on the basis that the court could have no reasonable confidence in the experts ability to act independently, and in accordance with his obligations as an expert witness.

The crux of Senior Master Fontaine’s judgement was the observation that:

“it is important that the integrity of the expert discussion process is preserved so that the court, and the public , can have confidence that the court’s decisions are made on the basis of objective evidence”

Despite the severity of the Order it was determined that the Claimant should be permitted to rely on a newly appointed expert.


The case highlights the dangers of instructing the expert whose evidence crosses the line into advocacy or takes a partisan approach.  Similarly, solicitors should ensure that they do not become involved in either drafting or negotiating a joint statement.

The dangers of a partial expert were also highlighted in the case of Bank of Ireland & Anr v Watts Group Plc[2017] EWHC 1667 (TCC), in which the expert’s conduct fatally undermined the Claimant’s case, and in which the Judge observed at the beginning of the trial that he had never seen a Joint Statement between experts that contained no agreement at all.

When approached by an expert for advice on a joint statement, legal advisors should refuse and ensure that their expert understands their obligations to the Court.


This article was co-written by Judith Hopper, Partner, and James Crabtree, Trainee Solicitor.


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