[Client] Champ Select Mastery Bug

So just a while ago I was in a ranked champ select and I was put into a pretty troll bug. Guy on my team got his ad banned and was upset so he says that he can use this glitch or something to play his banned champ, he was speaking in broken english so I didn't know what he was saying. So the way to reproduce the glitch was if you open your mastery page and click space twice, and then the mastery window will not close and you can't select champions. I tried it out and I couldn't select my champions except the ones lined up on the far right and got stuck with Zilean, who I didn't want to play. Luckily someone dodged our lobby, so now I'm just warning people to not try this. :P