plypoin, on 2019-January-08, 07:45, said:
♥ as Trump
West had no diamond left.
South stated "We have all the trump, the rest of the trick is mine". North on lead.
East called for TD, claiming he had one trick for the trump ( as south wasn't aware of outstanding trump).
Ruling ?
Would your ruling be different if North have no remaining trump ?
Law 70 C said:
2 -it is at all likely that claimer at the time of his claim was unaware that a trump remained in an opponent’s hand, and
3 -a trick could be lost to that trump by any normal* play.
*Footnote: For the purposes of Laws 70 and 71, “normal” includes play that would be careless or inferior for the class of player involved.
For a player who believes "We have all the trump" it is perfectly normal to enter his hand with a Diamond lead from Dummy.
If he were aware of the outstanding trump it would be utterly careless, but still "normal" as defined in the footnote to do so.
Ruling: One trick to the defence.
And no, it would not make any difference if North have no remaining trump.