The cut off was 79 WAM? So that's basically Distinctions only 
Also, since they don't take GAMSAT marks into consideration, if you get rejected once, does it basically mean you're never going to get in Medicine at Monash (I know there are other unis, but they're all extremely competitive as well)?
The cut off was the lowest score only though - it gave the person an interview, but not necessarily an offer. Due to the competitive nature of grad med programs, I would say your average marks would definitely have to be in the HD zone (for Monash, anyway).
With regards to doing graduate Medicine at Monash, out of the 75 domestic places available, 50 are limited to Biomedical Science students in their second last year (so it isn't possible to apply again for these 50 places - I think?), but the remaining 25 places are for anyone who has completed the relevant Monash degrees (you can apply as many times as you want for these). Don't forget there's also an undergraduate med program at Monash as well (with 200+ places).