I recently started playing Dota 2 just to have something a little different. I really like how they handle AFKs. For those who don't know, if you have a teammate disconnect during a match they have 5 minutes to reconnect. This gives just enough time for a playing to reboot their computer and log back into the game. If the player doesn't reconnect in 5 minutes the teammates with the AFK can quit the game with no loss on their record and no penalty. The enemy team still gets a win, but they receive slightly less from the win than they would have if the game had actually gone to the end. The player that ADK'd is then required to play a certain amount of time in a special lobby for other players that AFK'd. They cannot play ranked during this time.
I can see how this system could be be abused, but can't everything? I don't see it being abused in Dota 2 (other players might have seen it though), and I don't see why it would work any differently in league.