Thar is a bug with masteries...

I have no idea where to put this bug, but I happened to come across one when I played a game. I was duo queuing with a friend and when we were in champion select when I scrolled the masteries down I had HIS mastery labels but when I clicked on certain ones in order, the actual masteries were mine. However, if I clicked on the edit masteries it had my masteries everything normal. It stayed like that forever. Sorry no screenshot.