Often, when laddering, i press the find battle button, can't find a battle and then press cancel. Sometimes, a while later, a battle window still pops up. This is a known bug afaik, and afaik it can't be solved (yet). However, i have a suggestion which, if possible to implement, could nullify this bug:
When someone times out on team preview, neither players gain or lose points, nor lose deviation. As if the battle never happened.
If implemented, this might be abused through bad troll users trying to timestall people. But these could be kicked/banned/etc.
Edit:
I didn't think of this, but i do know of a solution to this (although it is veeeeeeeeery far-fetched and probably too much work for a bug of this size, so i'm fine with it if it doesn't end up happening. Here is what i propose:
When entering a ladder battle, you don't see the opponent's team immediately. You have to press a button. If you're away, and time out before pressing this button, you won't lose points. If you've pressed the button and then time out, you will lose points.
again, this is extremely far-fetched so idk
I'd really like to see this problem solved one way or another.