blackshoe, on Apr 7 2010, 05:50 PM, said:
So LHO retracts his trump, which becomes a major penalty card (which of course doesn't matter), and substitutes his ♠ spot. RHO may not withdraw his played ♠ spot (Law 47), so declarer, who played ♠Q, wins the trick. Now the ♠A and K, and LHO's trump, get played on the last trick. There is no Law 64 rectification for the revoke. Law 64C does not apply. One trick to declarer, the other to defenders.
The blame for the result lies squarely with RHO for not "discarding" the
♠A on trick 12

!! That, dear friends, is the lesson for the day
Jokes aside, I wonder if the caller should be asked if declarer was deliberately playing slowly. While it is quite probable that the position was reached in normal play at normal speeds, it is not impossible that declarer was "slow playing" to induce some kind of error by defenders; especially if defenders are much less skilled / experienced compared to declarer.
Would TD never ask a reasonably competent declarer how this 2-card position was reached and why declarer did not claim/concede the right number of tricks earlier in the play?