I am a Wash U Grad student and do research with adcom members. They are VERY numbers orientated in med school and residency applications. I have been told (from reliable sources for what it's worth), that it takes around a 32-34 to merit any consideration, though rarely, they consider a 30. Applying with a 30 is a waste of money.
My theory is that, though Wash U is near the top in medicine, it has an inferiority complex with other high caliber institutions. For nonmedicine areas such as economics, poly sci, bio, chem, business, etc. Wash U is good, but certainly not at the top. Accepting students with high stats is a very quantifiable measure of student body quality, and a way to maintain a good reputation. I personally think that it is BS.
I chose not to apply to Wash U. My stats are slighly below average, and I did not want to waste my money.