What about this (sort of applies): I've got a friend who got ~93 and he has applied for Commerce at Melbourne where the cut=off last year was 95.2. He has a SEAS application for underrepresented schools and because of that he left Melbourne as his first preference. What happens if he doesn't get a first round offer? Does he get an offer from his second preference or something? Or does he have to wait for second round offers? Sorry to hijack the thread 
he will just get something a bit lower on his list i guess
nothing to worry about
That is what will most likely happen but if that doesn't happen (and god forbid) and your friend does not get a first round offer, then they will have to wait until second round. When the second round comes out, if anyone rejects their offer from Commerce at UoM, then UoM will definitely re-consider your friend and other people who haven't received an offer.