So in your case, you can't do that but try to not show up at the border control either drunk or high or dressed like a bum and don't look nervous like you are smuggling something and you should be fine. Really, the way you are worrying about this and talking about your legal recourse just in case this might possibly happen to you, it seems you have already decided that they have a reason not to let you in. If you show up there with that attitude, they might pick up on it and not let you in, see what I mean. Do they have a reason not to let you in? If no, then why are you acting like it?