One of the things I think about in situations like this is how indestructible we consider ourselves to be when we're young. So indestructible that we often don't consider the possible outcomes to our actions. As we ag, our responsibilities increase and we experience more tragedy in our lives and we start to understand how precious the little things in life are. That's when we start to take more precautions.
For easily the first 10 years I bow hunted I didn't have a stand, I just climbed a tree and stood on a branch. Safety harness . . . . yeah right. Even after I started using tree stands I never used one. It wasn't until I started saddle hunting, relatively recently in my 50 years of hunting, that I can truly say I was always connected to the tree while elevated.
Purpose of this post? Just trying to point out that we don't always make the best decisions, especially when we're young, and don't be too hard on folks how've made a serious mistake. Hind sight vision is always 20/20. I'm sure if these people had it to do again they'd take the proper precautions.
Its situations like this that we should be thankful for the much maligned "Safety Police" as they at least point out the potential safety issues we may encounter. In the end though its up to each of us to assume as much (or as little) risk as we are willing to.