League won`t let me alt tab and bring task manager to the front.

Is there a way around this? I was on the loading screen in ranked at 100% with no indication that I crashed except for the unusually long time spent at 100%, I tried killing the client with task manager but for some reason I can NEVER get the league client to be minimized in order to actually use the task manager and kill it.

Just lost LP and was deemed a "leaver" when I never left my computer -.-