Is there any case law where a plaintiff was unable to make a rational decision about treatment?

25. I believe that Lord Justice Singleton's concern in Marcroft v. Scruttons, supra, stemmed from his doubt as to whether the plaintiff in that case was capable of making a rational decision. Not only that, there was some indication in the medical evidence that his incapacity may have been itself a consequence of the trauma induced by the accident. If this is so, it would appear manifestly unjust to cut off his recovery for failure to mitigate his damages through a rational decision as to treatment. The reasons of Lord Justice Denning are even more baffling. He attributes the plaintiff's traumatic state after the accident to a pre‑existing constitutional weakness and says it rendered the plaintiff incapable of making reasonable decisions. Yet he concluded that this was a subjective factor that could not be considered. This would appear to be carrying the objective test too far in that it overrides the "thin skull" principle altogether.