In a nation where people are sued all the time for innocent things, I'm not surprised. For instance, if you have a Koi Pond too deep, it may qualify as a public nuisance, or a pool. And if someone comes on your property without your permissions, falls in and dies, you can be sued.
I don't hunt. But if I owned one of these properties, I would probably be equally annoyed by it. A bunch of people, with guns? One trips and falls into your property, accidentally shooting someone? Yup, you get sued, and potentially lose your property.