One of the schools at which I interviewed was very clear on how the interview factored in to their decision making process. GPA/MCAT "open the door" so to speak. So as long as you meet the minimum requirements, they will look at the rest of your application. They give your application a score and invite you for an interview if you meet a minimum score. After your interview, they add in your interview score, the application score, AND a "score" for the GPA/MCAT. They didn't tell us how everything was weighted. Then based on your overall score, a decision is made.
While I completely understand why you are curious about this, and I have indeed asked the same question myself, I would urge you to focus instead on your interview. You cannot control how the school evaluates you compared to everyone else, but you can do the absolute best you can at your interview. Best of luck to you!