West led the ♦3 against the contract, ♦10 from dummy, ♦J from East and ♦A from me as South. And the opponents didn't ask any questions before leading.
As you can probably work out already, I had interpreted my partner's 2♣ bid as Stayman, and we had reached 3NT eventually, a contract that should have gone down with best defence. However, I had a feeling that the opponents would lead diamonds again even though I now had 9 tricks available. I played the ♥K at trick 2, ducked by East, overtook the ♥10 in dummy at trick three, taken by East, and luckily East then returned a ♦, so I ended up with 12 tricks. A complete swindle, I agree. But that's Matchpoints.
At another table 3NT was reached by the sequence 1♦- 1NT - Pass - 3NT. I found out later that the director had been called and the score of 3NT-1 had stood after West had led the ♠K. East had paused significantly (over 15 seconds) before contributing the ♠3, and West had continued with the ♠2 defeating the contract. North/South having called the director but then didn't want to make too much of a fuss, and not having the best of evenings congratulated their opponents on finding the best lead and let the result stand! (Very British. And yes, I had to laugh at that, too )
And, as always, thank you for your replies in advance. So...
1) Was it madness to try for overtricks here when the contract could go down?
2) Should I have given my explanation/interpretation for the bidding before the opponents led?
3) At the other table should the director have let the result stand given there was probably UI (Unauthorised Information), even though North/South called him and decided to then withdraw their grievance?