I'm dead serious. A pre-med blurting out the obvious statement with authority "higher MCAT does not equal better doctor" means nothing to me, although I generally agree. I do believe the MCAT to have a general correlation with the USMLE and specialty boards, and these tests all together do = a knowledgeable doctor in my book. You will see the stress you go through once you begin medical school, from wondering whether or not you should take the USMLE during your 2nd and 3rd years, to wondering why Columbia won't even allow you to rotate or interview for a residency position at their hospital. If you want this nonsensical jumping through hoops to end, then yes, you need to perform overall as well as MD students. This includes MCATs, USMLE, and whatever else you can think of. Stop with the "one test doesn't dictate whether or not I'm a good doctor" garbage. Nobody wants to hear excuses.
Lastly, yes, I do believe DO schools more or less have to accept people with lower stats, as the majority of people use DO as a backup (excluding anecdotal evidence of you or your friend who got a 40 on the MCAT and chose a DO school). I don't agree with it, hence why I think they need to raise the average GPA/MCAT for accepted students which can be done by capping the class sizes and stopping expansion.