The actual auction was a little more complicated.
2
♠ was not alerted, South assumed it was strong.
East led
♦A and when dummy came down asked about the auction. North volunteered (a little late, admittedly) that 2
♠ was weak and told East (incorrectly) that he could choose another lead if he wished. East didn't, switched to a low heart and North made ten tricks.
East maintained afterwards that if he had known that 2
♠ was weak he would not have doubled. I'm inclined to believe this, and I'm trying to work out possible continuations of the auction and which choices may be barred to whom at each step. (I'm not convinced East is entitled to know that 2
♠ is weak - that's an added complication - but I'm trying to cover everything).
I asked South what he would do if East passed, and didn't get a clear answer. He mentioned 2NT and 3
♥ as possibilities, but let's go with 2NT as the more likely one. North insisted he will bid 4
♠ over this and couldn't see any alternative. I thought this gave the matter an interesting twist, as South might now bid 4NT and they would end up in 5
♠-1. If I judged 3
♣ a logical alternative over which 3/4
♠ are suggested I would have to rescue them from this fate as I cannot assign any part of a score which includes an illegal action, so North would have been better off confessing that in retrospect he sees that he was ethically bound to support partner's clubs. Of course, they might still finish in 5
♠, 5
♣ or some other hopeless contract, but I think it's less likely now.
From your answers so far it looks as if 3
♣ could just about be a logical alternative.
North has unauthorized information from partner's failure to alert that 2
♠ has not been correctly interpreted, and must carefully avoid taking advantage of this, but if NS have no agreement about 2
♠, does it require an alert? The convention card made no mention of WJS, but does North's bid provide sufficient evidence that an agreement exists, and should I rule that EW were misinformed (law 75)?
Quote
BB2D2: Unless a player knows that his partners call is not alertable (or announceable) he must alert.
I've been tripped up by this regulation before. Does it mean that if there is any doubt in South's mind he should alert? If no alert is required then I think it is quite likely that the auction will follow the course it did, although the question still arises whether North's 3
♠ is legal.
As if that weren't enough, North complained that EW should have led or switched to
♣K and defeated 4
♠, so only have themselves to blame for their poor score.
Thankfully, East withdrew his request for a ruling, so I don't have to worry about it, but I'd welcome any further comments.