I think they have different meanings... First one can suggest that you shouldn't have lied to her at first (but then, later on, perhaps it would have been acceptable to lie). Second one indicates that the fact that you lied is the bottom line - for example, you shouldn't have lied and that was the reason that something went wrong. Indincating that no other argumention has any value. So the first one is more about timing, second one is about argumentation, I think.