When your winning against 5v4 and the AFKer or DCer comes back after 15 minutes at level 1 and feeds the enemy til they take back the game and win.
If your goin to go afk and leave the game for more than 3-5 minutes... don't come back. Just stay out of the game, PLEASE.
Playing in a 5v4 now, one person DC'd early on and we were still winning because our Shaco had like 10 kills early on and we managed to kick some ass. Then our afker/dcer returns and then zerg rushes the enemy over and over, getting slain over and over til they are fed enough to pwn us.