Yeah, dude, the way I see it: you're an interviewer at this giant school. You're interviewing someone who's maybe wearing their first real suit, and they can't believe how much it cost to look that boring. They've just spent four years or more putting everything they've got just to be sitting in front of you. They've spent thousands of dollars getting an application submitted, hours writing essays. They've likely spent hundreds of dollars just getting to that one interview, taking off time from work or school, with lots of pressure from people waiting back home.
Every interview is a @&$*! stress interview. The interviewer has the upper hand. If the student is falling apart, or can't answer a question, just let them show that, take note, and move on. There's no reason to be a jerk about it. No reason to pounce. They are your GUEST. Schools that don't respect that basic and soooooo obvious dynamic? I struggle to believe they'll turn out compassionate doctors.