Perceived partiality: in house experts in Clinical Negligence litigation

25/03/2026

By Manon Rowlands

LMN v Swansea Bay University Health Board [2025] EWHC 3402 (KB) offers a useful insight into the judicial approach to evidence increasingly obtained from in-house or regularly instructed clinical experts.

HHJ Dight CBE evaluated the instant expert’s evidence in light of her professional medico-legal background, considering whether her step away from regular clinical practice impacted upon the weight that ought to be given to her evidence. Increasingly, Courts are likely to question whether expert opinions might be influenced, consciously or otherwise, by their medico-legal alignment. This judgment highlights the importance of considering at the stage of instruction whether any particular expert’s deep involvement in one-sided litigation risks adverse case outcomes. Full and candid disclosure of professional ties, together with a measured approach to evidence is key to overcoming such judicial concerns.

LMN, a protected party, was born in 2003 by emergency caesarean section following a failed assisted delivery via forceps. He was profoundly asphyxiated at birth and suffered cerebral palsy and permanent neurological disability. Mrs Stanley, a qualified midwife instructed on behalf of the Claimant, provided within her expert report a list of fourteen instances of alleged breaches of duty by the Defendant in respect of the Claimant’s care.

The Judge noted that Mrs Stanley’s CV revealed that by 2018, over twenty years after qualifying as a midwife, she was working predominantly in medico-legal roles. Initially employed as a Litigation Midwife at Slater & Gordon, by 2023 she worked as a Medical Negligence Triage Manager at Leigh Day, with her clinical midwifery practice having become “very much a secondary role” [§23].

Mrs Stanley did not work for the Claimant’s own instructing solicitors. Nevertheless, the Judge stated at the outset that Mrs Stanley’s role “caused me to pause in evaluating the objectivity of the expert opinion evidence she gave” [§23]. The Judge went on to characterise Mrs Stanley’s evidence as “uncompromisingly critical of the defendant” [§23], noting that under cross-examination, “she stuck to her guns and was not prepared to yield” even where it would have been appropriate to moderate her position. The Judge contrasted this approach with the careful and reasoned evidence of the Defendant’s experts, particularly Mr Spencer, whose analysis the Judge described as logical and whom he considered able to provide “properly independent opinion evidence” [§93]. Ultimately, the Judge gave little weight to Mrs Stanley’s conclusions on negligence, and the Claimant’s claim was dismissed.

Practice Direction 35 is of course clear on general expert requirements; crucially that evidence should be “the independent product of the expert uninfluenced by the pressures of litigation” [35PD.21]. Experts must “assist the court by providing objective, unbiased opinions on matters within their expertise, and should not assume the role of an advocate” [35PD.2.2]. Extensive further advice can be found at the Civil Justice Council’s Guidance for the instruction of experts in civil claims, and with the General Medical Council (GMC) and British Medical Association (BMA).

In recent years, however, the Courts have been increasingly required to grapple with the subject of in-house or routinely instructed clinical experts whose independence might be questioned because of structural or financial ties. Mostyn J in Bux v General Medical Council[2021] EWHC 762 (Admin) provided a particularly detailed and informative discussion of conflicts of interest, perceived bias, and the duties of expert witnesses in a clinical negligence setting. The case was one in which a Doctor routinely accepted instructions to prepare medico-legal reports in respect of travel sickness claims from a firm of solicitors in which his wife was a partner. Mostyn J noted that:

“A conflict of interest will arise when an expert witness’s opinions are either (1) actually influenced, or (2) capable of being influenced, by his personal interests. The former state is obviously rare and where done consciously involves considerable moral turpitude. The latter state is more common and involves no wrongdoing” [§23].

Dr Bux had provided expert reports on “an industrial scale” [§6], and though not actually conflicted, the Doctor’s failure to candidly disclose his professional ties was fatal to his case.

Mrs Stanley avoided such criticism of conduct by openly disclosing her professional ties. Nevertheless, LMN illustrates an increasingly recurring theme in clinical negligence litigation; experts with heavy medico-legal workloads, especially those aligned predominantly with one side, are likely to find their independence more closely scrutinised. Even an entirely professional and honest in-house expert can be treated as conflicted where the structure of their role creates a reasonable perception of influence. This is the case even where those experts do not work directly for those solicitors for whom they provide expert reports. The Courts are alert to the possibility that litigation experience can drift into expert analysis, and the risk that an in-house expert may feel pressured to align their findings with their organization’s strategic goals.

The Judge’s scrutiny of the Claimant’s midwifery expert in LMN illustrates the importance of demonstrating openness and objectivity as an expert, particularly where regularly and heavily involved in litigation. Perceived partisanship arising out of career choices, particularly when combined with a critical tone and/or unwillingness to engage with counter-analysis, is likely to reduce the Court’s confidence in an expert. Full and early disclosure of professional ties, remuneration arrangements, and any institutional incentives is key to reducing expert criticism.