I can't find my copy of Landau's book, but wikipedia suggests that a 2NT rebid shows 16-18, and a 3NT rebid shows 19-20. A 2NT opening shows 21-24, 3NT 25+. Now this pair may have different agreements, and the TD should investigate them, but we aren't told what they are, so let's go with this. South has 19 points, 20 if you count his spade length. By the agreements just mentioned, he's too weak for a 2NT opening, and too strong for a 2NT rebid. South correctly evaluated his hand as not worth a 2NT opening, and then when he thought North might have stretched to respond 1NT, re-evaluated his hand downward even further (incorrectly, imo, as I understand EHAA). Then North, holding 9 HCP decided he was not worth 3NT opposite 16-18. This is not cheating, these are bidding mistakes (but see below).
The first thing I'm going to do is make it perfectly clear to both sides, but especially the SB, that the proper thing to do when there seems to be a problem is to
call the director. There is only one alternative to that: don't say
anything. Then I'm going to issue a disciplinary penalty to both sides for violation of the "best behaviour" policy. SB may wish to argue. If so, he gets one warning. If he doesn't shut up, he gets another DP.
South's BIT provides UI to North. What is the "I" here? What could it demonstrably suggest? I don't know, and at the moment I don't care. I'm with Barry — this is a 73C violation. North clearly did not "carefully avoid taking advantage of UI", because the fact that South broke tempo before bidding 2NT clearly suggested to North that South might be at the low end, or even a point or so lower, for 2NT. In spite of that, North passed 2NT.
Okay, now what?
Quote
Law 73F: When a violation of the Proprieties described in this law results in damage to an innocent opponent, if the Director determines that an innocent player has drawn a false inference from a remark, manner, tempo or the like of an opponent who has no demonstrable bridge reason for the action, and who could have known, at the time of the action, that the action could work to his benefit, the Director shall award an adjusted score (see Law 12C).
I'm not real happy with calling the SB "innocent," but never mind that. It was North, not South, who violated 73C. So what false inference did SB (or his partner) draw from North's "remark, manner, tempo or the like"? As far as I can see, none. So there is no basis here for a score adjustment. Ah, but wait! The law refers to "opponent," which means "a player of the other side". So this part of Law 73C applies to South as well as North. So again, what false inference did SB (or his partner) draw from South's "remark, manner, tempo or the like"? And again, no such inference is in evidence, so again there is no basis for a score adjustment.
I'm tempted to rule "result stands" and give North a PP for violation of 73C, but that will no doubt raise screams of outrage here, and probably from the SB as well.
Should we now look at 16 again? Probably. Back to "what is the "I", and what could it demonstrably suggest?" The "I" is that South was unsure whether 2NT is the right call. As it happens, South was right: 3NT is the right call.
But it is possible that North was considering passing over 1NT. In the former case, the "I" suggests bidding 3NT. In the latter case, the "I" suggests passing. Could we demonstrate that this "I" suggests passing over bidding? I'm in the "no" camp, in spite of what happened at the table. So again, no basis for a score adjustment. If your judgement is that the "I"
does suggest passing over bidding, then yeah, adjust the score. But at this moment, I'm not convinced. I still want to give North a PP for violating 73C, though, noting that 73C is a "must" law.
Is there another route to a score adjustment?
Quote
Law 12A1: The Director may award an adjusted score when he judges that these Laws do not provide indemnity to a non-offending contestant for the particular type of violation committed by an opponent.
I suppose one could argue that neither Law 73F nor Law 16B3 "provides indemnity" here, but…
Quote
Law 12B2: The Director may not award an adjusted score on the ground that the rectification provided in these Laws is either unduly severe or advantageous to either side.
One could argue that "result stands" is "unduly severe" to the NOS
and "unduly advantageous" to the OS, but this law says that none of that matters.
Note: I have made a distinction here between 73C's "don't take advantage of UI" and 16B3's "the UI suggests one LA over another". This is deliberate, as I think the distinction is built into these laws.
Perhaps I have misread the law. I would be pleased in that case if someone would show me how.