Grrrr... how would you feel?

Sorry you're having to deal with this...I'd be pissed too...and probably wouldn't have the self-restraint you have. 

The fact he didn't fire you speaks volumes...and I agree w/the others who've said there seems to be more to the story than you know.  Either someeon else is fixing the tip sheets and he came to you w/the one because she called about it...or someone's out to get you for whatever reason.  I'd compare the handwriting on the numbers if possible...and keep looking for a new job.  Whatever's going on there...you obviously don't want to get mixe dup in it.  And just for principle's sake...when you do resign...I'd mention the fact he took too much from your pay check.

Hope something else comes up soon.