I'm going to disagree...Although admissions offices are busy and applications are "confidential," I still think that that schools can talk "under the table," and I've heard several anecdotes from past applicants to support that. It doesn't mean they're discussing specific points from your appliction (as in, "Ooh, applicant B said x,y,z, in your 'Why X medical college' secondary essay but not in ours?"), but from what I picked up on during interviews, a lot of admissions heads and staff do visit other medical schools and know their counterparts, whether that means on a friendly/personal level or acquaintance level.
I have heard warnings from med students at different schools about writing letters of intent (in the manner of "I will come if accepted") to more than one school, because it could get ugly if admissions heads from those schools happen to discuss it. That doesn't mean that's BOUND to happen, but it certainly isn't implausible, especially at schools that traditionally compete for the same applicants and that either want to keep their US News rank or move up by keeping their admit numbers as low as possible. I hate bringing US News into the picture, but that's an "explanation" I've heard before, and with the way those rankings are heralded, it makes sense.
