Give a Leaving Game Warning when Leaving Team Builder After Everyone Clicks Ready

At this time if everyone clicks ready and you're still sitting there in the chat lobby (not the loading screen) and nothing is happening you can click the X at the top and leave. The client gives you no warning that you are actually leaving a game because no actual game has begun. But if you try to queue for another game it will tell you that you are already in another game. The only way to get back to that game is to close the client all together and restart the client and click reconnect.

This isn't much of a problem if you know you're in a game still and you're trying to get back to it. But what if you didn't know you left a game because you just assumed that you backed safely out of it because the client didn't warn you? This needs to be changed asap because I almost left a team because of this and I'm pretty sure that would get me Leaver Buster'd. I've tested this and it happens every time when my team is waiting for the loading screen (still in the pregame chat lobby).