First, as a dog owner I'm glad you dog is all right; second, I don't see this as a leashing issue. If your dog knows its name and has good recall just keep it within hollering range.
I know bird hunters use bells to keep track of their dogs, I don't see why you shouldn't. In fact, it's such a good idea I think I'll get a couple for for my dogs to wear in the back country.
I don't see a down side. In all likelihood predators will see/smell/hear you pet regardless of the bell; there's no reason I know that a predator would associate a bell with food; its a good aid for you to keep track of your dog in the brush; and it may well scare predators away.