Before leading RR asked about the 5H bid, as he had such good hearts that he though it was strange. ChCh replied "2 key cards and the queen of trumps", flippantly, "as MM always plays simple Blackwood". "Are you sure it shows the queen of trumps?" persisted RR. "Mea culpa", replied ChCh, "MM will stubbornly only play simple Blackwood, so just 2 aces."
RR led the king of hearts and declarer won, cashed the ace of spades and led the jack. He was going to run it, it is believed, but RR covered so the slam came home. SB hit the roof. "You deliberately initially gave a wrong response to RR", he began. "Without that, you might well have got the trumps wrong, but you knew from RR's question who had the queen."
"Rubbish", replied ChCh."Anyone not giving RR a chance to cover has not played bridge".
How do you rule?