For Malamud's similar case about building codes, the logical verdicts might be that privately-created text aimed at being building code does have copyright protection, but that it does not have the force of binding law until it has been put into the public domain by the government through agreement with the copyright holder. Getting a test case for this would be quite difficult though, as inspectors are notorious for exercising autocratic power and getting away with it.

It might also lead to the terrible situation where states just give up on building codes, but insurance companies continue to require them, creating de facto law through the backdoor of involuntary contracts.