in more complex situations where a number of actual or potential causes operate either consecutively or concurrently. For example, in Robinson v Post Office (1974) 1 WLR 1176 following an accident at work, the claimant had an anti-tetanus injection. Nine days later, there was an adverse reaction to the serum and brain damage resulted. No matter what tests the doctor might have performed, there would have been no sign of an adverse reaction within a reasonable time (see the Bolam Test). The doctor's reasonable decision to provide the standard treatment was therefore not the relevant cause of the brain damage because the claimant would not have been injected "but for" the defendant's negligence. Thus, in deciding between sequential contributions to the final result, the court must decide which is the more substantial contribution. In the High Court case of Ide v ADB Sales Ltd. (2007) and subsequent appeal (2008), regarding a mountain bike accident, two explanations had been put forward in court. One explanation was rejected by the judge, leaving the alternative explanation to be accepted and allowing the judge in accepting the second explanation to reach the conclusion that this followed from "the totality of the evidence", in this case that the bicycle was defective and the supplier was liable under the Consumer Protection Act 1987. Breaking the chain of causation Acts of a third party Whether the acts of a third party break the chain of causation depends on whether the intervention was foreseeable. The general rule is that the original defendant will be held responsible for harm caused by a third party as a direct result of his or her negligence, provided it was a highly likely consequence. So, for example, where the defendant has control over the third party, or where the third party is faced with a dilemma created by the defendant, the chain of causation is unlikely to be broken and the defendant will normally be liable to the claimant for the damage caused: Home Office v. Dorset Yacht Co Ltd. [1970] AC 1004. The continuity of liability is not imposed merely because the original negligence makes damage by the third party foreseeable, but where the defendant’s negligence makes it very likely that the third party will cause damage to the claimant: Lamb v. Camden LBC [1981] QB 625. In practice, however, the requirement that the third party intervention will usually break the chain