Patient
There's a chance that he knows his stuff, but there are other doctors who know their stuff who are also able to act professionally. Just a rude individual who doesn't know how to speak to people without trying to make them feel small. He was also very rude to a pharmacist I know who knows his practice very well. And after speaking to others, this doesn't seem to be an isolated incident. I would recommend, if you're looking into someone to take care of you, to look elsewhere.