I had the exact same problem with an interviewer recently. He came in with a preconceived notion to reject and kept moving the conversation towards that.

He was interviewing me for a Sr. Engg role , and his first question was what is the difference between Server side and Client side scripting. I took it in good humor and answered him. He stunned me by saying "That's not what I was looking for. You should have just said server side scripting runs on the server and client side runs on the client" :P

I know I should have hung up there, but I was referred by a friend so had to sit through the entire hour.