Summary of Court Opinion (Anonymised)

Factual and Procedural Background

This judgment concerns a personal injury claim brought by the Plaintiff against the Defendant, Company A, arising from a workplace accident on 19 March 2019 in which the Plaintiff sustained a serious crush injury to his right foot (including degloving and a burst fracture of the calcaneus). Liability for the accident was partly compromised, with the Plaintiff accepting a 20% reduction in damages for contributory negligence.

After nearly five years of treatment, on 13 March 2024 the Plaintiff underwent an elective below-knee amputation of the injured leg. The Plaintiff contends the amputation was caused by the 2019 accident; the Defendant denies this.

By order dated 18 September 2024 the court directed a trial of a single preliminary issue framed as follows: "Was the elective below knee amputation of the Claimant's right leg in March 2024 caused by the accident the subject of this claim in March 2019?" The preliminary trial took place over three days before Judge Walsh. Oral evidence was given by the Plaintiff and family witnesses (the Plaintiff's mother and stepfather, and an aunt), and by a venue proprietor. The Defendant relied on agreed lay evidence (including covert surveillance) which was not called orally. Orthopaedic expert evidence was given for both parties by Expert Harris (for the Plaintiff) and Expert Simmons (for the Defendant). Two Consultant Psychiatrists provided written reports and a joint statement (Psychiatrist Cooling and Psychiatrist Latcham); their agreement meant they were not called to give oral evidence. Both parties filed written submissions.

Legal Issues Presented

1. Whether the elective below-knee amputation in March 2024 was caused by the March 2019 accident (i.e. the factual and legal causation question posed by the court's preliminary issue).
2. Whether, if the Defendant's negligence is a "but for" cause, the Plaintiff's decision to undergo amputation constituted a novus actus interveniens (an intervening act breaking the chain of causation), such that the Defendant should not be held liable for the amputation.
3. Whether the appropriate legal approach is a pure factual causation enquiry or an enquiry that applies the legal concept of effective cause and fairness (drawing on authorities addressing novus actus and limits of but-for causation).

Arguments of the Parties

Attorney Smith (for the Plaintiff)

• Primary position: "But for" the Defendant's negligence the Plaintiff would not have suffered the injury that led (in time) to the amputation; the Defendant is therefore a cause of the amputation.
• The Defendant bears the burden of establishing that the Plaintiff's decision to undergo amputation amounted to a novus actus interveniens; absent that, causation is established.
• A finding that non-negligent medical treatment (i.e. an elective amputation that was clinically non-negligent) could amount to novus actus would unlawfully interfere with the Plaintiff's Article 8 rights and would represent a considerable and undesirable development in the law.
• It would be intolerable and unfair for a defendant to be able to escape liability by analysing a claimant's medical decision where the claimant was placed in a position to make that decision by the defendant's admitted negligence (relying on Emeh v Kensington A.H.A.).

Attorney Nolan (for the Defendant)

• The preliminary issue is not simply a "but for" question; the court must determine whether the accident caused the amputation in law — that requires considering whether the Plaintiff's decision or other supervening event has become the effective cause.
• Even if the accident was a factual cause, the Defendant contends the Plaintiff's conduct (including voluntary choices and the manner in which he presented to treating clinicians) broke the chain of causation.
• The Plaintiff must prove that the continuing symptoms and disability attributable to the accident were sufficient to make amputation a reasonable option; if not, the Defendant's responsibility ceases.
• The Defendant relied on covert surveillance and expert orthopaedic evidence to show the Plaintiff's pre-amputation function and behaviour were inconsistent with the level of pain and disability alleged, and that the amputation was not clinically necessary.

Table of Precedents Cited

Court's Reasoning and Analysis

Overview of legal approach:

• The court acknowledged that the Defendant's negligence was a "but for" cause of the injuries sustained in the 2019 accident, and that a low but real risk of future amputation (assessed at approximately 5–10% on the joint expert evidence) existed from the outset.
• However, following authoritative guidance (Corr and Spencer, and the textbook on causation), the court proceeded to ask whether, in law, the Defendant remained the effective cause of the amputation or whether the Plaintiff's own conduct constituted a novus actus interveniens which made it unfair to hold the Defendant liable for that outcome.
• The court framed the task as a holistic assessment: it must consider the totality of the evidence (documentary records, lay witness evidence, covert surveillance, and expert evidence) to determine whether the amputation was effectively caused by the original negligence or by a subsequent supervening event.

Assessment of evidence and credibility:

• Witness credibility: The court found the Plaintiff to be an unreliable and not wholly credible witness for multiple reasons identified in the transcript (inconsistent accounts about the reasons for job loss, discrepancies in reported symptoms to benefit agencies, implausible explanations for observed conduct on surveillance, and conflicting accounts about the conduct of medico-legal examinations). The Plaintiff's mother and other lay witnesses were found to have limited evidential value in part because they relied heavily on the Plaintiff's account and in some instances speculated beyond their direct knowledge.
• Surveillance evidence: Covert surveillance (taken over an extended period) showed the Plaintiff walking with heel strike, walking unaided on many occasions, and engaging in a range of leisure activities including Airsoft, darts and other physically demanding pursuits. Except for a single day when the Plaintiff was seen using a crutch (on the day he attended a medico-legal appointment), the surveillance did not show regular use of mobility aids in the UK during the surveillance period. Both orthopaedic experts agreed that the footage was not consistent with the Plaintiff's clinical presentation at medicolegal examination, but disagreed as to its interpretation.
• Expert evidence: The court preferred the Defendant's orthopaedic expert (Expert Simmons) to the Plaintiff's expert (Expert Harris). Reasons included: Expert Harris's shifting estimates of amputation risk during oral evidence without clear new factual or literature-based grounds; Expert Harris' failure to engage in detailed analysis of the surveillance; and Expert Harris' reluctance to qualify his position despite identified "red flags". Expert Simmons provided detailed analysis of surveillance, was consistent in explaining that the gait shown was not antalgic (no limp) but often involved heel strike and normal stride, and identified the absence of objective orthopaedic signs to justify amputation.
• Treating clinicians and information available to them: The court noted the absence of direct evidence from treating surgeons and observed that the treating clinicians had not been provided with the full picture (notably the Plaintiff's participation in Airsoft and the covert surveillance), facts which limited what could be made of treating clinicians' consent to proceed. The court rejected any inference that the absence of treating clinician testimony obliged a conclusion that treatment had been non-negligent.

Synthesis and legal characterisation:

• The court found that while the Plaintiff had ongoing symptoms and had not made a "complete" recovery, there had been demonstrable improvement between late 2021 and the months immediately prior to amputation (notably from August 2023 into early 2024), with surveillance evidence showing effective, often normal, function including heel strike and walking unaided.
• The court concluded that the amputation was initiated primarily by the Plaintiff (he had researched and pressed for amputation, and the process was not primarily led by treating clinicians) and that the Plaintiff had not informed surgeons of some relevant activities (notably regular Airsoft participation) such that the treating clinicians did not have the "full picture."
• Given the weight of the surveillance and the court's preference for Expert Simmons' interpretation, the court held that the Plaintiff's pre-amputation level of pain and restriction of function — as required to justify the amputation as arising from the original injury — was not established to the standard required; the Plaintiff's decision was therefore not an involuntary act compelled by the Defendant's negligence.
• Accordingly, the court determined that the Plaintiff's deliberate act in electing amputation was of such impact and degree of unreasonableness (or was otherwise a supervening event) that it eclipsed the Defendant's earlier wrongdoing and broke the chain of causation.

Holding and Implications

Holding:

ANSWER TO PRELIMINARY ISSUE: NO. The court answered the question posed in the preliminary issue in the negative: the elective below-knee amputation of March 2024 was not caused, in law, by the March 2019 accident for which the Defendant bore admitted liability.

Core legal effect and immediate implications:

• The court held that the effective cause of the amputation was the Plaintiff's own conduct (a supervening event/novus actus interveniens), and therefore the Defendant is not legally responsible for losses arising from the amputation.
• The decision rested on application of established principles about the limits of "but for" causation and the role of fairness in attributing legal responsibility (Corr; Spencer), together with an evaluation of the totality of factual and expert evidence — in particular the covert surveillance and the court's assessment of witness and expert reliability.
• The court expressly rejected the Plaintiff's submission that a finding of novus actus in circumstances of non-negligent medical treatment would necessarily constitute unlawful interference with private life or a major development of the law; the court considered such a result to be consistent with established authorities where the claimant's conduct eclipses the defendant's wrongdoing.
• No broader legal innovation was declared: the ruling applied existing novus actus and causation authorities to the facts and did not purport to create a new legal principle. The court distinguished Emeh on its facts and made clear that the present case involved different factual circumstances (a voluntary decision not compelled by the defendant's conduct).

Practical consequence for the parties:

• The Defendant will not be liable for damages relating to the elective amputation performed in March 2024. The Defendant's admitted liability for the original workplace accident remains relevant to other damages not affected by the finding on the preliminary issue (the judgment does not address other heads of loss beyond the scope of the preliminary issue).
• The court made no finding as to the Plaintiff's motive for electing amputation beyond concluding that it was not caused by the Defendant's negligence; it expressly declined to speculate about motivation where the Defendant had not pleaded a positive case on motive.

Judge: Judge Walsh

Hearing dates (trial of preliminary issue): 17, 18 & 21 July 2025. Judgment delivered in October 2025.