Something that crossed my mind reading through Bulbapedia when I read that Pok Balls can break.
So, when a Pok Ball gets damaged, Pokmon cannot be called back in and needs to be fixed. But when a Pokmon is inside a Pok Ball and it breaks it cannot be called out. That seems like an immense design flaw to me. It means that they are essentially trapped in one.
What if a Pok Ball gets destroyed beyond repair? If a Pokmon is outside its Ball, they'd be released. But when it's inside when it gets destroyed, what does that mean? It is something that hasn't really been an answer, I think...
Are they trapped forever? Are they considered 'dead'? Or would there be some sort of 'emergency release'?