We had a ruling at the Club under Law 45.4. (b) which surprised me.
I was under the impression that any card called for by declarer is a played card.
The director ruled in favour of declarer on the following,
Declarer (south) led from his hand and west ruffed.
Declarer called a card from the table which effectively was an underruff.
He immediately realised he had made a mistake, & corrected this to a higher trump & claimed it was an "unintended designation".
I thought that once a card is called for, it is played.
The clause referred to above seems to cast doubt on this. Was the director right? If he was wrong can you please provide an example of where clause 4(b) in Law 45 applies.