Bob,
As I recall it, that case was for Harbor Town and the courts ruled that they could copy hole design ideas, but had to take down the replica of their iconic lighthouse. I never quite understood that one.
So, to some degree, yes, it appears to be true that you could copy any design idea (Lord knows, we all copy them to a degree) but the problems come in calling it XXX - the sequal or copying anything that would really be unique to them. That said, the Ike Bridge has been copied, many courses have azaleas and/or pines, etc. I suppose a famous course could go to court over a lot of things, but common ones like bridges and vegetation would be hard to prove you copied their bridge, and plants are natural.
The issue of who owns a design is not an insignifgant one to gca's. Standard contracts (if there are such things) typically allow the gca to maintain the rights to the "intellectual property" and plans are considered "instruments of service" rather than the product itself. I specifically limit the rights of owners to resuse any plan or idea for another project, but retain the right to do it myself.
Of course, I am worried about two things - first, I would rather get paid again if they build another green to my idea. Second, there have been some odd duck legal cases where an Owner uses (or reuses) a green plan and the original gca gets sued despite not even being involved with the project just because his name was on the plan and the injured party added them to the lawsuit.
The weirdest one I ever heard of from my E and O insurance agent was an East Coast firm who provided a free green plan in the interview process that included a retaining wall. They hired a different gca who was cheaper, but told them to use the other firms plan, which they did. However, they didn't engineer the wall and it fell down. The club sued the gca who did the original concept plan for a faulty design even though they had nothing to do with it, other than drawing a line as an idea on a piece of paper only to have "their" design rejected, at least as far as they knew.
So, I also put disclaimers in contracts for using plans only for their intended use - concept plans as concepts, construction drawings for construction, and using all plans ONLY for the project under agreement. I am tempted to send a set of final plans to the owner (which, while I own them, there is some legal mumbo jumbo that grants them the rights to keep a copy for their records) but without my name on them, so that if they get out in the public domain, no one will sue me after building off a crappy Xerox.
Now, if the course in question ever gets the scrutiny of Merion, it will be harder for some future historians to figure out why no name is on the plans!
Another interesting question - I have heard of a gca threatening to sue over the use of their ideas, esp. when they were produced in a design competiton. One sent such a letter to my client after I casually told him that the client who hired me DID like some of his routing, and instructed me to use a few of those corridors. And to think, I was trying to compliment him, as I knew it was tough for him to lose that project to me.
He did NOT put any kind of copyright mark on his plans and thus backed off his claim of copyright protection.
But I wonder if gca's dead or alive might consider suing other gca's as a revenue source in these tough times? I think it would be hard to win, but what if I am building a version of CC's semi-famous "toilet seat" green? Is that closely enough tied to them to give them legal rights to the idea? How much does it have to change to be an original idea - 5% or so? What about a Mac Boomerang Green that was fairly distinctive, and with all the books out there now, known as one of his trademarks oddities? Would I hear from his estate? Or anyone building a Biarritz, which was clearly a CBM idea and quite identifiable?
I hope those things have passed into the public domain, because versions of them are too cool not to reintroduce to the golfing public who will never get to see the dozen or so originals, either because they lie on private clubs, or have been remodeled out of existence.