Another reason why things are different in the United Kingdom: the Law Lords have just ruled that it is up to Parliament, not themselves, to decide whether to adopt the controversial "loss-of-a-chance" doctrine in medical malpractice cases. The doctrine allows patients to sue for damages even if medical misadventure most likely did not cause the bad outcome (so long as they can argue that it worsened their chances to some degree). Gregg v. Scott, Lords; Court of Appeal; The Lawyer. By contrast, it's common for state courts here to switch to the more liberal recovery rule simply on their own say-so, as the Wyoming Supreme Court did recently. (case/continuation, both PDF). Now doctors in Wyoming are talking about working through the state legislature to overturn the doctrine, but of course that's a lot harder than winning a legislative fight over whether to adopt it in the first place.
Law Lords: "loss of a chance" doctrine up to Parliament