Switching to opponents team mid game

I was playing Ultimate team and was winning 3-1 and the opponent queued a pause but when before it got to the pause menu some glitch made me and him switch teams. He wasn't playing anymore and was idle with my team and I believe it wasn't his fault.  I couldn't pause or leave so I ended up closing the game and it ended up giving me the win so I'm not mad just wondering if anyone has experienced and similar thing