Clearly all TDs should be carrying that guideline around with them before ruling on a claim. Actually it has no relevance whatsoever in this case, as the heading of that minute, and the White Book section, is: Law 70E: Unstated line of play in claim [WBFLC] It is assumed declarer would see cards as they would be played and to take account of what he would see Here there was a stated line of play, a heart to the ten on the second round of the suit, so the TD cannot apply that minute. By implication, with a stated line of play, declarer does not take into account what he would see, but follows the stated line willy-nilly. For what it is worth, the 19% of people who voted to allow the claim in the Bridgewinners thread you linked are also wrong for the same reason.