I've shot a lot of animals with a lot of different things, but I can't say I've ever seen twist rate make a difference. It all seems to depend on three factors; velocity at impact (not MV), the individual construction of the bullet, and the biggest variable of all is exactly what the bullet hits once it enters the animal.

I certainly can't say that rotational velocity doesn't play any part, but if it does, it seems to just get lost in the myriad of other factors.