Worked example 1
Alex stabs Ben, who is taken to hospital. Ben dies after a nurse mistakenly gives the wrong drug. Advise whether Alex is the legal cause of Ben's death. [10 marks]
Show solution outline
Issue: Whether Alex's stabbing is the legal cause of death despite medical error.
Actus reus — conduct: Stabbing is a voluntary act — clearly satisfies conduct element of homicide.
Factual causation (but-for): But for Alex's stabbing, Ben would not have been in hospital. Factual cause established (contrast R v White where victim died independently).
Legal causation: Must be operating and substantial cause at time of death (R v Smith — original wound still operating). Thin skull rule — take victim as found (R v Blaue).
Medical negligence (novus actus): R v Jordan — palpably wrong treatment may break chain (rare). R v Cheshire — only if original injury becomes merely background; medical treatment normal even if negligent will not break chain.
Application: Stabbing is serious wound — likely still operating cause when wrong drug administered. Nurse's error must be so independent and potent as to make stabbing insignificant (Cheshire test).
Conclusion: Alex likely legally causes death — medical error usually insufficient to break chain unless wholly unrelated to original injury.
Exam tip: Work through voluntary act → but-for → legal cause → intervening act in order.