Based on what I know of my class, there are probably a good 5-10 ACCEPTED students with MCAT scores at or below 30. This is yet another reason why I still contend that Duke is NOT a numbers *****; and using a school's average MCAT and GPA isn't a great indication of one's "whoreness."
I think that applicants who are accepted with scores that low tend to be minorities though, as some data suggests that under-represented minority applicants of comparable intelligence do more poorly than their non-minority counterparts on standardized tests. But I know that Duke interviews tons of people with 30's and below each interview cycle...again, it's really not just about numbers.