BALONEY! One more "official" who wants to let you know that he knows it all. If you warn him, you warn him, and that's it. Once is enough, I don't care when you do it, as long as it's before he shoots again. Tell that "official" to keep his day job.
Jay, maybe you should discuss this with your boss. LOL I'm also at the US Open and decided to discuss this with Ken Shuman who as most of you know, is the most proliferate professional billiards referee in the country. He agreed that you should tell your opponent when he approaches the table on his inning that "he's on 2" and he should also acknowledge that he understands and agrees at this point. This is the way I've always ran my tournaments and also the way they explain it at the players meeting of the Derby each year. It's only fair. The objective is not to try to trap your opponent in such a situation, but to make the situation clear to both parties.