lamford, on 2019-October-28, 09:16, said:
If 2H is alertable if intermediate but not if weak, then it is illogical that South did not bid 3D because he thought 2H was weak, and I would reject the NS argument.
lamford, on 2019-October-28, 09:19, said:
We are told that intermediate jump overcalls require an alert, but not weak jump overcalls, so firstly we need to establish that from someone familiar with the alerting regulations in force.
LH2650, on 2019-October-28, 12:18, said:
That he would have bid 3 diamonds (which makes 4 on reasonable play), if he had been properly informed. There is also the issue of whether a new suit by advancer is commonly played as forcing.
LH2650, on 2019-October-28, 12:24, said:
A weak jump overcall does not require an Alert, so the table did not know that there was no agreement. Only East knew there was a problem.
On the assumption that the jurisdiction here is the ACBL, the regulation says that weak jump overcalls do not require an alert. Intermediate or stronger jump overcalls do require an alert, as do artificial jump overcalls. The ACBL system card has a line like this for jump overcalls: "strong x intermediate x weak x" where the x's represent checkboxes and the first two words and their checkboxes are in red, indicating alertable, and the third is in black, indicating not alertable.
South did not say that he would have bid 3!D if he had been properly informed. What South said, according to the OP, is that if 2!H had been weak he would have bid 3!D. The
auction says that 2!H is weak, but the
card says it's intermediate. South chose to believe the card rather than the auction. He did not ask the opponents to clarify the situation, nor did he call the director before he passed.
As director, I would investigate whether the agreement is "weak" or "intermediate". If the former, then South was misinformed by the system card. If the latter, South was misinformed by the failure to alert, but this doesn't matter because if there had been an alert he was definitely not going to bid 3!D. In the former case, it seems to me Law 21B3 applies, and I would look at adjusting the score.
The question whether 2!S is forcing is a bit of a red herring. If a score adjustment made on the basis that South bids 3!D is under consideration then West won't get to bid 2!S, and if no score adjustment is contemplated, then there was no infraction, and East can do what he likes, including passing a forcing bid. Further, how it is "commonly played" is irrelevant. The question is "how does
this pair play it?"