I assumed this would be your response, but I'm not sure you are correct.
noun: idiom; plural noun: idioms
a group of words established by usage as having a meaning not deducible from those of the individual words (e.g., rain cats and dogs, see the light ).
"In this case, the client's position seems to have been that (a) through error four members of one team sat in the wrong seats, preventing a valid result in a Swiss match"
This seems unlikely unless no one noticed that Grainger was sitting on Marty Seligman's lap
Drew Casen may want to reconsider opening 1NT with a small singleton ...
"Play a convention, system, or treatment knowing it is
illegal (CDR 3.2 and 3.7)
90 days probation and or up to 60 days Suspension*
10 Up to 50% of Disciplined Player’s total
"In order for the trump coup to operate, declarer will need to ruff 2 minor-suit cards in dummy and then take 3 rounds of hearts ending in his hand."
Why does declarer have to take the 2 ruffs in dummy before cashing the 3 hearts?
"The opponents are not playing d.d. and there is at least a live possibility that they will go wrong (most probably by ducking the second trump)."
I think you should concede the point. There is not a lively possibility that they will go wrong by ducking the 2nd ...