Legal Question in Civil Litigation in Georgia

I'm sure you can get varied opinions on this, and we only have a couple sentences of one side of the story (and their might be several sides), but my opinion is that the instant you allowed your child to get in a golf cart with a 16 year old boy, there is SOME level of accepting the risk that this will happen. 16 year old boys driving fast or careless in a golf cart (motorcycle, ATV, etc.) should probably be expected. That is what kids do - even those who might otherwise be relatively responsible. The flip side is that a person (or parents) are responsible for the damage they cause to others, and that might be injuries from driving recklessly. What is missing from your side is what your son did or said in the ride. Was he encouraging it or willingly going along for the ride? You don't say what the injuries were or how much the medical charges were, but based only on the little we know I'd say either work it out amiably, or pay the expenses and write it off as a lesson learned.

While I'd want more information, you probably have grounds to sue their parents and it is possible that they have vehicle or homeowners coverage that would pay. Unless the injuries are very minor, see a lawyer ASAP and do not discuss it with the neighbor before doing that.