And then when the snake doesn't eat the rat, you have a rat waking up who is in a lot of pain. I don't know about you, but when I get hit on the head, it hurts like heck and it doesn't make me a very happy person. And you possibly have a brain damaged animal, depending on how hard they were hit. Leaving them to live like that, in my opinion, is animal cruelty.
My animals get either f/t, pre-killed, or live. No stunning rodents in this house. I am very careful when I feed live. I am always there to intervene should something go wrong. So far, nothing has gone wrong. I always have tongs in hand because if a rat or house does happen to get wrapped up in a bad position, I can easily stick the end of the tongs in the rodent's mouth and let him chew on that until he dies, instead of him chewing on my snake. I have been keeping snakes for 4 years now and not a single one of my snakes has been bitten by a rodent while in my care.