[CRASH] pressing TAB during victory/defeat banner loading

Windows 8.1

I was pressing TAB to see team stats as the "Defeat" banner was about to load during an ARAM match, and the client froze. I could ctrl-alt-del to get to task manager, but could not kill the process because the screen kept defaulting to the frozen fullscreen client (now a blank screen because of the ctrl-alt-del).

After a minute or two, the client finally crashes with a windows "try to find a solution and close" error popup.

I have been able to get this to occur 3 of the 4 times I've tried, by simply repeatedly pressing the TAB key, starting just prior to banner loading and continuing until freeze. Banner never fully loads when a freeze occurs.