I'm not asking the interviewer to talk about Markov chains, or even know much about them. I'm asking that he be able to form a coherent question on the subject. You would expect an interviewer asking about politics to at least be able to ask reasonable questions about politics and not say something like: "so how long have you been interested in politicizing, and voting, and things like that?". A good interviewer can tailor the interview to the audience, a bad one can hardly hold his own (this guy was an example of that).