In one of my Nevada CCW renewal classesthe instructor told us we should never shoot in a remote area. He told us that many guns used in crimes are actually taken from target shooters in remote areas. Since I was given this advice I never allow someone to approach me while I'm shooting in the boonies. If it is a remote area I always shoot where I can see people coming and I keep my eyes and ears open.
If your situation would have happened to me I would have immediately jumped in the car and avoided them as much as physically possible.
Paranoid? Maybe... but, it might help you avoid this type of situation in the future.