B v Governor of Brockhill Prison, Ex parte Evans, an important case in English law, involved the unlawful detention of a prisoner. The governor had sentenced the prisoner on the basis of an interpretation of a statute which had originally been supported by the courts, but which had subsequently been held to be wrong. It was clear that the governor was blameless, but the sentence raised questions as to whether the new interpretation of the statute should apply prospectively only. The majority of the Law Lords held that, on the facts of this case, it was not appropriate for the interpretation to apply prospectively only, but all of them also accepted that the development of a rule might, in appropriate circumstances, apply prospectively. Lord Slynn of Hadley reasoned that "there may be decis