Not true. I have killed rats to feed to my snakes multiple times. I do this by snapping the neck with a single quick jerk so that the rat does not suffer. On more than one occasion i have had rats go into a seizure like state where they will spazz out. The movements may be fast and constant or slow and random. Either way the rat was dead and kept moving. If i kept pushing air through the lungs and into the throat of an animal it would keep producing noise. The snake can do this by closing its mouth on the lungs of the rat and pushing the air out or by laying on the rat.
All in all the rats were dead and could still move and produce noise in a constant manner
Money can't buy happiness, but it can buy snakes and that's pretty close
You are right animals act a lot different when you brake there neck then when you squeeze or cut its neck.