Ethical Blackwood bidding

... several times in a row. Going into the 5th round of the round robin yesterday, we had 43 on a 40 average and seemed to be playign a competent pair. On the first 3 hands, they stopped in 4D making exactly and bid 2 making minor suit games, only one of which did 3NT have a chance. On the 4th board, they have the uncontested auction: 1H-3H-4NT-5D-6H. Seems fairly straighforward. No major breaks in tempo. Partner asks about the bidding. 3H was a limit raise and 5D, after about a 30 second hesitation, was 0 or 3 keycards. Partner leads a spade from 4 small and I play the queen, taken with the ace. Declarer draws trumps and leads the king of diamonds, with QJTx showing in dummy, along with Kx of clubs and a few small spades. So, she takes the A and leads another spade. I didn't have a chance to make an encouraging signal for clubs, so, from my partner's point of view, logically, the only way we're beating this hand is if I had started with KQ of spades, still an unlikely holding. And I wind up going to bed with my ace of clubs.

I should have called the director. I know there is nothing the director can do about the declarer being an idiot and bidding a slam knowing he is off 2 cashing aces or about him forgetting his partnership agreement. In this case, I am much more likely to believe it is the ladder. If I were playing against a novice, I could/should shrug it off and think, well, he didn't know any better. I can accept losing 11 imps like that once in awhile.

The guy wouldn't respond when I asked about what he was thinking or why he gave misinformation. He never looked at his card during or immediately after the auction so he wasn't reminded by that. I actually didn't look at the card either. So, my problem with this is that he seems to have bid thinking that 5D showed 1 or 4 keycards because no reasonable bridge player (which I assumed he was) would have gone on to slam with only 3 of the 5 keycards. And I know he isn't obliged to tell us that he forgot their agreement, but is it ethical or proper to bid the hand one way and then after the bidding remember what your actual agreement is and tell the opponents that actual agreement? Personally, I think he should have just said "I'm not sure whether we are playing 0314 or 1430 blackwood but you may check our convention card." There is no guarantee we would have found the defense to beat 6H if we are not convinced that declarer holds 4 keycards, but we certainly would have a better chance.

On the other hand, at the end of such an auction the guy should be able to tell what 5D is immediately without pause for thought. I mean, he was just thinking about this 15 seconds ago and now he needs another 30 seconds to think before telling us. That seems fishy. Perhaps at that point we should have called the director. If there are eny experienced directors reading this, I'd like your opinion.