Patricia Andrews and Ors v Kronospan Limited

Permission to rely on expert evidence may be revoked where serious breaches of the duties governing expert independence undermine the court’s confidence in the expert’s ability to comply with those duties. The court must assess the seriousness and extent of the breach, whether the expert’s independence or reliability has been compromised, the prejudice to the parties, delay, cost and the availability of alternative evidence. Repeated private consultation between an expert and the instructing solicitors about the substantive content of a joint statement may justify revocation, even where the conduct falls short of the most egregious cases. Group litigation and substantial expenditure do not make revocation disproportionate where the integrity of the expert process has been materially undermined.

The claimants in group litigation concerning alleged dust, noise and odour nuisance sought to rely on Dr Nigel Gibson as an expert in dust analysis and dust modelling. During discussions preparatory to joint statements, Dr Gibson exchanged drafts and substantive information with the claimants’ solicitors and sought their comments. The defendant applied to revoke permission to rely on his evidence, relying on breaches of the duties imposed by the Civil Procedure Rules and Practice Direction 35.

The claimants accepted serious transgressions but argued that revocation would be disproportionate, given the length of the proceedings, the number of households affected, the costs incurred and the resulting delay. The central issue was the appropriate sanction for the breaches.

1. Application granted. The claimants’ permission to rely on Dr Gibson as an expert in dust analysis and dust modelling was revoked.
2. Experts owe the court an overriding duty under CPR 35.3. Their opinions must be independent and must not be influenced in form or content by the exigencies of litigation. The restrictions in CPR 35PD.9 apply equally to legal representatives.
3. The court applied the guidance in BDW Trading Ltd v Integral Geotechnique (Wales) Ltd [2018] EWHC 1915 (TCC). It distinguished that case on the facts because the present case involved continuing contact, repeated substantive comments on progressive drafts and the disclosure of information about the experts’ discussions. The court also treated the principles in Dana UK Axle Ltd v Freudenberg FST GmbH [2021] EWHC 1413 (TCC) as relevant, while distinguishing its exceptionally egregious facts.
4. In deciding the sanction, the court considered the seriousness and duration of the breaches, the apparent advocacy by Dr Gibson, the absence of evidence explaining his conduct, the claimants’ expenditure and the prejudice, delay and cost caused by replacing him. The test was not limited to proof that the expert had actually changed his opinion.
5. The cumulative conduct undermined the basis on which permission had been granted and left the court with no confidence in Dr Gibson’s ability to act as an independent expert. Revocation was therefore appropriate and proportionate. The claimants could instruct replacement experts, subject to further case-management directions and possible conditions.
6. The court urged future solicitors and experts to follow the guidance concerning concise joint statements, agreed agendas and the prohibition on negotiating or drafting the substantive content of experts’ joint statements.