In the phrase "to get off scot-free", the word scot has nothing to do with Scotland or the Scottish. It's an Old English word meaning fine or penalty.

I once overheard a tour guide confidently tell a group of visitors to Edinburgh that the phrase was coined after one of the "grave robbers" Burke and Hare became a witness for the prosecution and was released. Burke and Hare were actually Irish, and they were murderers.