Scots law is actually a separate issue from the current Scottish Parliament, in fact it was used as one of the arguments for having one. I remember it being set up: I voted for it.

The UK constitution, if it can be called such, is made up of numerous contradictory documents, but Scotland retaining its own legal system was one of those. It has some everyday features not found elsewhere in the UK like procurator fiscal, and until recently the "not proven" verdict. (I was at a murder case a couple of years ago where the panel (accused) was given a "not proven" verdict.)