I've had the same thing in a few of my interviewers. A few of them have even tried to explain what my chances were of acceptance after the bulk of the interview was over. Usually it was something like, "I think you would make a great doctor, and I hope you get in, but keep in mind that I can't make the entire decision myself so don't take this as an acceptance." Some even said they would try hard to fight for me, but couldn't guarantee anything. One of my interviewers wasn't even on the adcom, and was basically like, "I wish there were more physicians like you, but I have very little say in this process, I just fill out a form and mail it to the committee." I wanted to say, well what are we even here for then!! Also, he said that after he basically insulted all my life decisions, and ranted for about 15 minutes about how much he dislikes physicians. That interview was a very dark timeline.
I think most interviewers are just very friendly and want to be on your side and help you get in if they can. I doubt I'm such a good interviewer that I just blew them away and they were in love with me. As stated above, I apparently talked way too long, so who knows. If I go 0/4 I'll report back and retract all statements.