Select Keys Randomly Stopped Working

So I was playing katarina on SR earlier today and was quite enjoying myself, when 15 minutes or so into the game I discovered I couldn't back. This happened quite randomly too, as I'd backed twice during the game before this happened. After spamming a bunch of keys in confusion, I realized neither my q or r keys were workingtoo, though w and e were working just fine??? I asked my team mates if they were experiencing the same bug, but they responded negative. So it was just me. Someone said they'd had a similar bug once before and suggested I simply restart the game, so I did, which fixed everything nicely. I figured I should still report the bug and hope it doesn't happen to me again as I'm wary of the leaverbuster queue >_>