In terms of ranked play, it could be something along the lines of afk + early surrender means a LOSS PREVENTED or something.
The problem is, ultimately, all systems to protect the general LoL "public" against toxic behavior can be abused. And that sucks, because that means ragers, afkers, trolls, and bots will just keep on being a problem, no matter how many times they get reported, suspended, or banned.
While I like that Riot is trying to solve the problem via LeaveBuster updates, I truly think the implementation of fail-safe systems would work after about a month of being in place, if not only for the reason that abusers would be quickly dealt with by the tribunal. Or, if Riot is really concerned, they could watch for borderline cases and police a bit. I know we all keep thinking this is going to be a big issue, but um....DotA is doing just fine with these systems and that's with little to no VALVe interaction.