Dummy not presented correctly

[David Burn]

Had a situation where Dummy was laid out with what looked like 2 Diamonds to the 10, and 5 Hearts to the Ace. Defender lead the JD to the second trick and Declarer followed, only to suddenly discover the Ace was actually a Diamond and not a Heart. It was relocated to the head of the Diamonds, but now the Defender wanted to change their play (partner hadn't played at that stage) saying she would not have lead the JD if the AD was in the correct position.

Even though it is really up to Dummy to make sure the cards are presented in the correct manner, I believe there is some responsibility on all players to assess all aspects of the cards, including cards in the wrong suits, only 12 cards showing because one is hidden under another, etc, etc. On that basis, and the fact that it was exposed to partner, I required the JD to be played. Is that correct / reasonable, or should I be more sympathetic and allow the player to change their lead card.

[niftyneville]

The responsibility for the correct presentation of Dummy's cards rests with Declarer. See Law 41D

Dummy's Hand
After the opening lead is faced, dummy spreads his hand in front of him on the table, face up, sorted into suits, the cards in order of rank with lowest ranking cards towards declarer, and in separate columns pointing lengthwise towards declarer. Trumps are placed to dummy's right. Declarer plays both his hand and that of dummy.

Failure to do this correctly is an infraction for which Declarer is responsible. It is a fallacy to suggest that defenders have any responsibility for the placement of dummy's cards.

The defender should be allowed to change his/her play.