I'm not sure, but it seems a quebecism. If I'm right, it could mean sth like: I have nothing to do with it (je m'en fiche/je m'en fous).
I don't know what you mean with "sacrer means to leave". I've never heard sacrer in this way!
I concur with what the French-Canadians have said. S'en sacrer in Quebec means roughly the same thing as S'en foutre does in France. Both can also mean to leave but in different contexts such as sacre le camp, fous le camp.