I think this sort of thing happens to a lot of people that get consumed in learning to play guitar. My best friend ws that way when he was learning to play guitar. He got so submersed in learning theory and technique and watching videos and reading books that he assumed that he knew everything there was to know about playing guitar. So, when I would tell him something about playing... or try to show him a lick... He would only tell me that I was wrong and that I COULDN'T play that lick becuse it "technically" goes off key... even though the lick I was playing was derived from a SRV lick, using the same box of notes as he did. I got pretty annoyed with acting like he knew everything but he grew out of it. I think that this guy eventually wil grow out of it too. Once he realizes that he, in fact, is not some guitar prodigy and there are a ton of people out there that are much better than him... He may continue to be as arrogant as he has been. Take any comments that he makes with a grain of salt and let it float away.

BTW, My friend ended up growing out of his arrogance... and since then he has become when of the best guitar players in the area... I can't even challenge him... he's that good. Until he got over being over confident all the time I was just as good, if not better. So it worked out for the better for him.