So, this is a thing that happened.
I went into a comp game and did deathmatch while you wait. While in deathmatch, I got the “Rendering device stopped” error, so I closed and restarted my game. When I loaded back in, I was at the hero select screen for the comp match with the title screen overlayed. After my hero loaded and I was in the first person camera, I still had a free mouse like I was in the title screen and could not move my character.
Screenshot (I apparently can’t post links):
imgur dot com/FMFFBuz.png