S's 2♦ bid was alerted as a weak jump shift. N hesitated before bidding 2NT. S, holding 14 HCP and a long ♦ suit, raised to game. Director summoned by defenders.
S says he did not hear his partner's alert and explanation. (I'm reporting this as it was explained to me, so down with the cat calls.) Director ruled at the table that weak jump shifts were marked on the card and was the partnership agreement. N had properly alerted his partner's call and defenders had received an accurate description of their agreement. He further rolled back the contract to 2NT (making 5), stating that S had no LA to pass given the auction and their agreement. The howls of protest began and everyone went home unhappy.
When this scenario was presented to me, I was inclined to agree with the director. I was not impressed that S "had not heard" his partner's alert, when both defenders had. It strikes me that this is a L16B.1.(a) "unexpected alert" that awakened him to his mistaken call and he should pass 2NT. With a typical 6-8 HCP hand with long ♦ that would be expected by his bid, I can't support his bidding again. On the other hand, had his bid not been alertable and he had realized his error before the auction had been completed (without any verbal cues from his partner), I would allow him to continue bidding as his partner and the opponents would be equally confused by his torpor (not exactly L75C., but more like L40C).
As always, I look forward to your learned counsel.