That's definitely not how this process works.
As Goro and Master pointed out correctly, you have no way of knowing how your interview went, or how heavily weighted it will be in the final admissions decision. If your interviewer is a strong advocate for you, it may be the deciding factor, and the same is true if your interviewer recommends against your admission. You really have no way of knowing what your interviewer thought of you, either. You may really hit it off and think it went great, and your interviewer may like you quite a bit personally and think you'll be a wonderful physician but still think you aren't a good fit for that program. Some will be warm or stern or standoffish to all applicants, equally. Likewise, some interviews that last less than 30 minutes went better than others than lasted an hour, with the same interviewer. You really don't know; your own interpretation of your interview experience is just that and cannot necessarily compared to another unique applicant's experience.
Regardless, the interview DOES matter, and by the time you get to make it past the first few rounds and make it to the interview stage, I think it's a huge part of the final decision.
I never downplayed the interview process. I said that while it was important, it is not necessary to ace it 100%. Because the interview is subjective, nobody can really compare, so you're right. I went with my gut feelings at these interviews, and I can say that the ones I felt comfortable I was accepted, and the ones I felt uncomfortable in, I was also accepted. It may show that I'm just not good at objectively gauging myself.
Since the interview is open file, and the interviewer knows already what you're all about based on your primaries, secondaries, EC's, and stats, my assumption was that they've already formed an opinion about you. They already like you because you've been invited to the interview. The interview process was just to gauge what you're like as a person. Everyone knows it is impossible to really know a person from just one interaction with an interviewer, whether it is 30 minutes or an hour. I would bet just about every applicant would try to say that the school they're interviewing at is a good fit for them and how they're a good fit for the school and give a pretty good convincing argument.
The admissions committee works by the interviewer reporting his/her findings, and the committee votes. If your interview went badly, then obviously it would hurt. If your interview just went okay/average, your stats/EC's/well written primary and secondary/LORs may make up for it, depending on the mood/thoughts of the admissions committee. If your interview went super well, but your stats are well below average of the school, you may also be waitlisted. It is not necessary to completely ace your interview 100% and get every single question asked correctly. You just have to be likable and demonstrate that this school is a good fit. My point was that everything is important, but there's a range. I would assume, based on how other schools vote, is that they assign points to each category. (Interview, stats, EC's, etc.) Obviously none of us knows what really goes on in adcoms, but that would just be my guess.
What makes this more interesting, is that a current medical student with ties to adcoms did say you're ranked on the waitlist based on your stats.
Some of the interviews I've been on told us that the interviewers have no say in the admissions process. Some are even closed file. They just report what the applicant says electronically and the committee decides. There are also some schools which accept the majority that were interviewed. Every school is different, so I can't really comment on Rowan's process.
We really don't differ in our opinions, really. We just phrased it differently. Master wrote that the interview was the sole determination whether you are admitted or not after being granted an II, and that stats/EC's don't matter after that point. I'm saying it's the whole package (combination of all your application materials, LOR, interview) and that it may not be necessary to completely ace your interview to get accepted. I apologize if I had said anything to offend others on here.