I had a bad interview at my top choice too; I know how it feels afterwards, couldn't get myself over it. Just kept thinking over and over about how I should have answered those tough ethical questions and that I should've been better prepared. In retrospect, now I don't feel I could've done any better considering the questions he was asking me. I told my premed advisor about it, and she said intervieweres sometimes tend to ask toughest questions to their best applicants, or that they just want to spark off conversation that interests them. She also said that since interviews are so subjective they don't factor in as much as other aspects of your app. in their final decision. If you are a strong well-round applicant, interviews won't make or break your chances. Now, I am still waiting to hear..but I feel like there isn't much I can do. Asking for a reinterview is probably a bad idea as suggested by many to me. So I am just waiting. Hope things work out for you.