Wow, I've never heard of shit like that.
I probably wouldn't do anything. If the guy did that it would be clear to me that he was trying to piss me off. The reason behind this could be anything: he might be unstable, he might just be an asshole, or he might have a fucking gun. So I wouldn't take any chances on something like that.
Now if he attacked me or something, of course I'd defend myself. But in a case of someone trying to piss me off, I believe it's best to walk away with your life than stay and lose something.