Pokeball design question

[chanveil]

I know that pokemon can come out of their pokeballs on their own, sometimes at inappropriate times (psyduck, wobbuffet, etc). It can happen often and I'd be mad if my pokemon keeps coming out of it's pokeball at the wrong time!

Why aren't pokeballs designed to be opened only by the trainer and not from the inside? Is there some safety reason?

[Mikachu Yukitatsu]

Misty was mad too. Poor Psyduck.

My first guess is that Pokeballs must have the emergency exit. What if something happens to the trainer? Also, is a Pokemon supposed to be a prisoner of the Pokeball?

A cool reply to this topic should have included references to certain episodes and stuff, but unfortunately I'm out of ideas here right now.