Inability to leave a bot Custom Match

So a buddy of mine likes to make custom matches of nothing but bots when we wants to try out a new champion and learn a few things. He logged in, created the match 4 bots and him vs 5 other bots. I hopped on to play with him and he clicked leave game. No biggie right? Except he cant leave it. He has to exit out of the entire client and relog back into it. The worst part? Even when he logs back in it puts him back into that custom match. He cant leave it. How do we fix this?