You find people like this all the time.
I work in a trade and there are always guys that say the know so much but over time they prove what little they do know. Starting out I had a great journeyman tell me never to talk about what you know to someone else but let your work prove your knowledge and you will get more respect.
I hope I can make that kind of impact on a apprentice some day. He not only taught me how to do my job but taught me how to be humble as he humbled me many time.LOL.
I know how people like that can drive you crazy but they will show themselves sooner or later.