Garen And The Nexus [GAMEPLAY]

I was playing an ARAM game as Garen, and as we were attacking the nexus I pressed Q for the auto-attack reset. Not only was I unable to double hit the nexus, I wasn't able to hit it at all. I just sat there staring at the beauty of the nexus model, ignoring the mouse frantically clicking to attack the nexus and secure the win. I had to run over to a Heimer turret and hit it to remove the Q. At that point I was able to attack the nexus again.