This is indeed a very odd interview.
Imagine you are interviewing for a Managerial post, but the interviewer being assigned to conduct the interview is mostly clueless and mind you, this is not the least of the joke here, the interviewer is an Executive that is supposed to be your potential future subordinate if you get the post. One as a seasoned Manager, might as well being assigned to interview a C suite candidate on behalf of the company owners. Not the interviewer's fault nonetheless, this is indeed Sr. Management's fault through and through. I kid you not, RED FLAG!