[kb49]

EBU

This problem happened recently in our club. These are the details. West was playing in 4S. On the tenth trick they noticed that East (dummy) had two cards left and the other players had three cards. The missing card was found among the cards already played by dummy. How do you proceed to rule on this problem? Which law covers an infraction of this kind by dummy? If they check through the played cards and disagree about what had happened how do you rule?

What actually happened was that the remaining cards were played out. West making 10 tricks. It was then discovered that dummy had played two cards to a trick and as a result had later revoked. As dummy had won the revoke trick and subsequent tricks two tricks were deducted from west. It was an uneasy ruling because there was a feeling that dummy could not revoke. However most people felt that the Director had made the correct ruling. What do you think?

[RMB1]

There is a law (Law 14B1, Law 67B2) but that does not cover how "the Director establishes which trick was defective".
With some practice, this is not difficult - especially if they players properly point their played cards correctly - without exposing too many played cards.

There is no penalty for a revoke by dummy but Law 64C should be applied to restore equity. The two tricks transferred by the TD was not strictly legal but it may have restored the result to what would have occurred without the card being misplayed.

[blackshoe]

When was the director called?

Dummy certainly can revoke, but as Robin says, the rectification in Law 64A does not apply; instead the director adjusts the score to restore equity.

Edit: I would add that if dummy can't revoke, the director's ruling (transferring two tricks) is clearly wrong.