So this just happened. I went into a 3v3 Twisted Treeline game, we were on the left side. Our enemies didn't show anywhere for a few minutes so we got suspicious and went over to their fountain to see if they were just afk or something. So I used my trinket to reveal them, my game crashed instantly. My 2 friends I played with confirmed that it happened to them as well. We have no idea why.
It seems the enemy team couldn't connect to the game at all; as soon as they would connect, they would gain vision of their fountain and instantly crash again. We don't know if it's an issue with a particular skin one of them had, or just a map issue. Either way this is insane and totally gamebreaking.