Would it be possible to finish a game with somebody else's game when he has a disconnect/leaves/whatever?

This popped into my head today.

Would it make sense? Would it be fair? It tastes bitter to win simply to somebody on the other team leaving. It is down right awesome to win 4v5 (if the leave goes on for more than a minute, not just the last hits onto the nexus after somebody DCed in the last teamfight.. you know what I mean)

you could have people join games of similar (ranked/normal-) elo by a button from the main-menu.

discuss please