I think your question is flawed because 27-30 is a range you really need to parse out -- is it 30 to 35 or 27 to 35? Because the former was already borderline while the latter really wasn't at a lot of places.
Either way, except for the couple of schools that only care about your highest score, most would prefer b, the person who took it once and did well. But there is a lot more to the application than MCAT scores so either or neither of these guys might be getting into med school.