RE: Another falls and is in a body cast.
Worry more about the auto accident going to your hunting area. Worry more about being overweight and in poor health. Worry more about getting shot by a fellow hunter.
The chances of falling from a tree stand are very, very slim. Should I wear one ? Probably. Do I ? Rarely. My perrogative, my choice. I'm a middle aged man in good shape and health, I wear my seat belt, I eat healthy and I excercise four to five days a week at least. That I don't wear a safety belt in the woods is a choice that I make because I'm comfortable where I am. I do have a very good safety harness that cost $100 I believe, I just don't wear it very often.
If you want to be really safe, don't climb a tree. Or don't go hunting. Or wear a helmet.