Canceling evolution (CLOSED)

Is it possible for a Pokemon to cancel evolution even if they aren't holding an everstone through outside influence? I was thinking of the games but, if you Bitchslapintheface startle the Pokemon will it cease evolving for the time being?

In my opinion, it should be possible provided that they're startled during the evolutionary process... but it would have to happen every time they level up.

Thanks Mew that sounds good, this may be closed.