George,

IMO, Fire alarm systems are required to be grounded even if there is no sticker in the panel alerting the installer to the requirement. 760.9

Again, IMO, this is not an equipment ground being used to facilitate the operation of an overcurrent device and all thats left for it to be is a grounding electrode conductor and it could connect to any point on the grounding electrode system or to any other grounding electrode conductor. If connected to a metal water line, then 250.52(A)(1) should apply. I think you're on the money for requiring the connection to be in the first 5 feet of pipe.

Few things are harder to put up with than the annoyance of a good example.