Besides, being really difficult to read, the thread just goes to show that you can't assume that some random person "of authority" knows the law. He gets some misinformation when calling the trooper's office, and confusion ensues. If you read the law, it's pretty clear that you can bring a cased handgun into NY for certain matches with some limitations.
Of course, you may get stopped, and even arrested by an officer who is not aware of this law, but I think that's status quo for a lot of the less popular laws. If you want to compete, I would say make sure you have good proof that you are competing in the match, good proof that the match is a valid one, and probably a copy of that section of the law with you. Oh, and probably try to avoid speeding and running red lights on the way there
It is interesting to note that states like Vermont that don't require any sort of special permit for a pistol are left out by this law as it specifically requires the individual to have "a pistol license or firearms registration card" from their home state.
Mike