OK, here comes Biology 101.
* The movement of the guts is called peristalsis, and it will continue until the cells run out of energy. It's what moves stuff through the gut. Small, rhythmic contractions of smooth muscles (not controlled by voluntary nerve impulses). So, even if you shut dow the CNS by killing the deer, it will keep going for a while.
* Yes, deer have gall bladders, but the gall bladder is a small bag of green stuff firmly atached to the liver. The spleen is close to the liver and looks somewhat similar to the liver. It is flat and reddish. Kidneys are in their own little pouches along the spine.
The story of killing the chickens reminds me of watching a couple of city guys trying to kill a goat by stabbing it in the chest with a kitchen knife. Slow, but it eventually died. And it was a good thing because the noise was awful. But the goat did manage to get them pretty good a few times before it died. We tried to tell them to just slit its throat and let it go, but they weren't going to let anybody tell them what to do.