Leaving a game during series...

When you try to close the game while you're in a match, you get a message that says that if you leave, it'll end your league serie or something. I was wondering if that applied as soon as you left or if you left without comming back. The reason I ask that is that sometimes I have to restart the game, since it just crashes during loading... And obviously, I'd like to play, not just wait for something that won't ever load. So yeah. Thanks!