I don't understand what's so hard about just calling him and simply asking what the deal is? You showed it to some of your friends, and upon further examination, it looks a bit strange. If he's a friend, I'm sure he'll let you know what's up. And if he's just a 'dealer' or whatever, just ask some very specific questions and you'll know if he's trying to lie. Try to have an intelligent conversation to get to the bottom of it...no need to 'get pissed' just yet.

Another reason to only deal with friends and not "dealers" that you only half trust.