ChCh, South, found a nice ruse to make his impossible slam at the North London Club this week. RR, North, thought that South had three key cards, and decided that grand was too ambitious and settled for a small slam. West led the jack of hearts and ChCh won in dummy and thought for a good five minutes. The TD came to the table and said "you are behind, please hurry up". ChCh replied, "Sorry, I was torn between two lines and they seemed identical." Now ChCh led the six of spades and SB, East, put in the king, necessary if South had AJ9xx but fatal here. The 0% slam rolled in.
SB was furious. "Why did you think for so long in a hopeless slam?" he asked. "And what were the two identical lines you saw." He ranted on. "You simulated having AJ97x when the two lines of running the queen and low to the jack are indeed identical, 16.6%, provided I always find the falsecard. You could have been aware that your remark would mislead."
How do you rule?