As an interviewer I always asked candidates if they have any questions for me at the end regardless of how the interview went. It's up to the candidate if they

As an interviewer I always asked candidates if they have any questions for me at the end regardless of how the interview went. It's up to the candidate if they want to end the meeting early. When they have questions for me, I treat the last 10 mins as if I am having a chat with a person who happens to be very interested in what I'm working on.