Teams-of-eight. The auction, starting with East, went:
2♦(1)...P...2♠(2)...3♥
.P......3♥
(1) Multi (2) pass or correct to 3♥ with a weak two
When I arrived at the table to deal with the insufficient bid, South said "If I understand the rules correctly, I can just do this" and placed the 4♥ bidding card on the table. He was promply informed that he did not understand the rules correctly, and taken away from the table where I established that when he bid 3♥ he was just trying to raise his partner's overcall. I explained that if the insufficient bid was not accepted he would have to repeat his 4♥ call and that partner would not be barred from the auction, although I may have to award an adjusted score if they reach an unplausible contract by means of the insufficient bid.
We returned to the table and I explained the options. West then wanted to speak to me away from the table, so we left the room. He asked whether, if he accepted the insufficient bid, the attempted correction to 4♥ would be unauthorized information to North.
I must say this is a level of foresight and deviousness I don't usually encounter among C-team players. I told him that if he accepted it, all players would be entitled to know that South had bid 3♥, but would only be entitled to guess at the intended meaning. The attempted correction to 4♥ would indeed be unauthorized to North, who must strive not to use this to his advantage. We returned to the table, West accepted the call by passing, and then North decided he wanted to talk to me away from the table to clarify under exactly what circumstances he could bid 4♥. I explained it as best I could, we went back, I invited them to call me back if there were any problems, and they continued playing. (I did just check to see if East had anything to say to me in private, in case he was feeling left out, but no, he wasn't.)
I wasn't ever called back, and I didn't find out what happened. Just out of interest, do you think I got the ruling right, and what would you say if North had bid 4♥ and it made (as it did at other tables)?