Hmm...

Does this friend of yours struggle with anything on a personal level? Maybe he's not a c_nt, but instead dealing with personal issues and doing a poor job at coping with the stress. I know that I used to have serious personal issues and I'd blow up at anyone and anything in my path. There was no excuse for my behavior because it was 100% my fault, but I can now see where people are coming from when they act out. They may have poor anger control.

It is possible he is a c_nt, though -- but I'm just saying maybe there's more to his behavior than what you see.