1C = Precision, 16+ artificial, 3H = Spades and a minor (like Michaels), 4C = Pass or correct for partner's minor
Trick 1: High heart lead
Trick 2: Trump switch, won by the jack in dummy
Trick 3: Spade finesse
Trick 4: Ace of spades, throwing a heart
Trick 5: Heart ruff in dummy
Trick 6: Club ruff in hand
Reaching this position, with 5 tricks in for NS and 1 trick in for EW
Declarer leads a spade, and east thinks for maybe 15 seconds and ruffs with the diamond ten. Declarer says "diamond", and as dummy is moving to play the diamond declarer says "wait I mean club". East calls the director to get it worked out.
1. My thoughts are that whether declarer can be allowed to play a club depends on why he said diamond. If it's because he missed east's card then he is trying to change his mind which is not allowed. But if it's because he always meant to say club but his mind simply stated the word for what he was looking at (east's card) then he hasn't changed his mind, he meant to call a club all along so he should be allowed to do what he intended. Is all that accurate?
2. If I'm correct in 1, how does the director go about determining which it is? What if east and north disagree on the reason 'diamond' was said (with south and west having no opinion)?
3. Does it matter how long east took to make his play? Ie, is there a "sominex proviso"? Obviously there is no such term in the laws, I just wonder whether it's a relevant factor in determining declarer's intentions.
4. Does it matter if declarer was pointing at a club when he said diamond? What if south says he saw that north was looking at a club when he said diamond?
5. Is there anything else relevant, either missing information or another possible factor that could matter?