This is hunting gear related more than bow related.
I have had the misfortune of dropping things from my stand as I unload my pack. Actually, it it almost for sure I'll drop something back to the ground. From grunt calls to thermos bottles, I have dropped almost everything I own at least once.
A good friend of mine who has the same issues gave me a fix for this disease. And yes, it is a disease. The proper name for it is Disfunctional Involuntary Propulsion of Meaningful Equipment or D.I.P M.E. for short. There is no cure, only a way to survive the disease.
Here's how to:
Take a very large treble hook (it can be a weighted hook if you wish) and file the barbs completely off. Tie on about 50 feet nylon string. Wrap the string around the shank of the hook. Now, store it so there is NO POSSIBLE way you can drop it from your pack.
You can easily retreive ("fish up" as I call it) items that you drop from your perch without climbing down. For hard to catch gear like thermos bottles, you may want to tape on a loop of string or something. Since you removed the barbs from the hook, you can "fish up" clothing without having to worry yourself sick trying to remove the hook.
I have "fished up" quivers, calls, sandwiches, jackets, and many more items with this simple, but, revolutionary piece of equipment. I hope that this helps some one in need.