This was an interesting hand from a teams match last night, and the match was in the balance until a ruling on the above board. North's 3♦ bid was painfully slow, and South 'found' some extras with his 3NT shot. West led the king of clubs, and continued clubs. Declarer crossed to a top spade and led the jack of diamonds on which East played the ten very smoothly. After an anguished think, declarer ran it, and notched up an unexpected overtrick.
East-West called for a ruling, as it was felt the 3NT bid might have been influenced by the BIT. If you impose a Pass on South, then East-West wins the match by 2 IMPs. Another point made by South was that failing to cover with Q109 was a classic example of a "serious error" unrelated to the original infraction, as dummy's card was surrounded. Indeed it was given as such by a TD seminar in San Remo. East was indignant, and indicated that playing low was the only chance to beat the contract. If you deny East-West redress, then North-South win the match.
So two issues to rule on. The 3NT bid, and the serious error.