All my keys just shut down.

I was playing a normal draft match. at around the 13 minute mark, all my keys just stopped working. none of my abilities worked, I tried to type in chat to tell my team but the enter key wouldn't register to bring up chat. So then I thought if I disconnected and reconnected, maybe that would work. But not even the escape key worked. all I could do was throw basic attacks and move, I couldn't use abilities or even speak. It cleared up and went back to normal after about 5 minutes, but it still freaked me out.