I think I got the diagram right. Repeated here:
North is dealer, south is dummy, West's cards are irrelevant.
East leads
♥10, North plays
♣2 from dummy (South), west plays an irrelevant card, North plays
♣J thinking he's playing
♥J, then starts to claim, first leading
♦2, stating he will take two diamonds and concede club.
Declarer North has claimed. Play ceases. Ignore the
♥ lead from East for the moment. As it was not North's turn, his line of play statement is completely invalid. In addition, he has revoked (Law 61A), and the revoke is established by the claim (Law 63A3). The revoke may not be corrected (Law 63D). Now we adjudicate the claim. East will be deemed to lead his heart (after all, that's what he did), North will win and lead his small diamond, so South gets the last three tricks (East, btw, gets the 10th trick - after all, he won it in the play) (Law 70). Now one trick is transferred to EW (Law 64A2). Law 64C regarding equity for the NOS, does not apply. In effect, had South not revoked, he would indeed have taken a heart and two diamonds. Instead, he took... a heart and two diamonds, and then gave one trick to EW because of the revoke.
Note: East's
♥ lead was subsequent to North's
♦ lead; East played while North was stating the line of play for his claim. If play had continued, that is, if there had been no claim, East's heart would be deemed the proper lead, and North's diamond would be withdrawn (Law 53C). In this case, North's revoke will not have been established, and he would have to correct it. Which leads to the line of play he stated with his claim.