Brad:
I believe the case study of the hole at Essex G.C. was one of those I read that was supplied to me by the NCA--I also spoke with an NCA consultant lawyer about golf liability situations. Although on the face of it, and the way you present it, the case would seem to have gone against the club unnecessarily when one considers the logic of "assumed" or "prior risk", there were a few other pertinent details in that Essex case that should be presented.
I probably have the case study around here somewhere but from memory the suit was brought by the homeowner against the club but only after some non-legal negotiation with the club apparenty failed over time. The house had been there for a long time, as you said, probably establishing some logic and basis for "prior" or "assumed risk".
However, the complaint/plaintiff/homeowner had recently bought the house and was more than slightly surprised how much his property was getting pummeled by golf balls (apparently a situation that was anything but recent--eg "assumed" or "prior risk" on the part of the previous homeowner(s) ).
It's also my recollection that the new homeowner considered suing, or did sue, the realty company (and perhaps the realtor) for not informing him of this risk (which a realty company legally should have done and is required to do) but there probably wasn't potential satisfaction there financially and the problem with the golf hole would've still existed even if the owner won a suit against the realtor.
So the owner began to negotiate with the club for some sort of satisfaction as to his property being pummeled by golf balls but, as often happens in these pre-existing situations the club didn't take it seriously enough and ended up in court and we know the rest of how the hole eventually got redesigned in some more than minor way.
But, as you mentioned, these kinds of situations are causistic and very individual legally, although there are apparently certain legal guidelines that any judge and jury anywhere are likely to review on previous case studies of golf related danger.
And that, generally speaking, is what the NCA lawyer was trying to explain to me. In layman's terms that would be that the law looks at golf and golf courses as inherently dangerous and the most the law expects a club, particularly an existing club, for instance, to do is the best they can under the existing or even pre-existing situation. That means the law expects them to only do the best they can (which ironically may even mean only doing nothing to make the hole MORE dangerous than it's always been) and not to have to create an atmosphere that completely removes potential danger which the law apparently realizes is an impossibility in the real world.
A good example or analogy to the Essex situation would probably be the 15th hole at Merion East. If a new homeowner bought the property across the street (a property that has always had a good number of incoming golf balls) I seriously doubt that homeowner would get much satisfaction under the law from a realtor who forgot to inform him of the situation or from Merion to redesign that hole somehow.
The reason being although "assumed" or "prior risk" may not run with the land in a legal sense as a recorded or established easement, for instance, the situation would logically be viewed legally as so obvious that the law would likely decide the prospective homeowner should have known to assume that prior risk or just go find himself another house somewhere else.
So in a real way, and certianly in some situations, the legal logic of "assumed" or "prior risk" apparently does exist.