Bugsplat on Loadscreen

Randomly bugsplatted. Couldn't even hit "Yes" to the prompt because the black screen locked me out of my primary monitor. I was only able to hover on the second monitor, which clearly shows a completely black screen and another League window where it was 'concluding' the game that I didn't get points for because I was a 'leaver.'

I can't be a leaver if the client doesn't even let me join.