Yeah I don't think they would know. But also, if you have to reapply, take a good look at your application and think about what held you back. It's possible it was a low MCAT, in which case retaking may be a good idea. But it could also be other things, like extracurriculars, in which case it may be more worthwhile to spend some time improving those instead. Just my $0.02. Good luck and I hope you get in this cycle!