this kind of shit happens all the time, cool people hook people up properly, nobody's gonna give you a couple grams extra and ask for it back, so don't worry about it, somebody said he's "testing" you to see if you are trustworthy, doubt that, he's just a cool person and hooked you up fat, next time you see him just be like thanks for that half man, that was a fat bag, he'll probably just be like, no problem man.