  On the first point, Common Lawyers ordinarily think of precedents as constituting the law up and until they are overruled. Once overruled the later decision is (normally) given retroactive effect, so the law is changed for the past as well as the future. But when a case is distinguished it is not often thought that the law was one thing until the later decision of a court, and now another thing.  The law will be regarded prior to the later decision as already subject to various distinctions not mentioned by the earlier court.  Indeed part of the skill of a good common lawyer is grasping the law as not stated by the earlier court: learning that cases are ‘distinguishable’ is a staple part of common law education, and no common lawyer would be competent who did not appreciate that the law was not to be identified simply with the ratio of an earlier decision. Common lawyers do not, then, conceptualise distinguishing along lines analogous to overruling.