Weird bug involving the client closing in the middle of a game...

This was weird. It's happened once in the past, but it was a long time ago (a year?).

During a game the screen glitched, went black, and then was laggy for a bit. Then the game finished, we lost, but w/e.

When the game ends, there's no client loaded anymore. There's a league tile on my toolbar, and I can hear the sound of people talking in after-game chat, but I can't un-minimize the tile on the toolbar, and in my programs-running list there is no league.

I right-click-close the tile on my toolbar, restart league, it starts up as if nothing happened....

In this case the game's outcome was already set; we were losing hard. But if that would have happened to another game, it might ruin it for my team. The client-closing thing is more annoying, though. Has this happened to anyone else?