It has been suggested in the past that the test in Bonnington Castings and McGhee was particularly suited to cases involving industrial disease, whereas the approach in Wilsher was more relevant to medical negligence cases. However, the recent case of Bailey v Ministry of Defence [2008] EWCA Civ 883 shows that this simplistic analysis is not always appropriate. The case involved negligent medical treatment. The medical experts were unable to say whether the negligent treatment was on the balance of probabilities the cause of the claimant’s cardiac arrest and brain damage. They were able to determine, however, that the brain damage was caused by the negligence working together with the natural progression of the claimant’s condition (i.e. factors working together cumulatively rather than independently). The Court of Appeal therefore applied the Bonnington test and concluded that factual causation was satisfied because the negligence materially contributed to the risk.