I don\'t think Fremantle ever applied for a trademark for \"LIghtning Round\". There\'s only one record in TESS (regarding \"game equipment set sold as a unit comprised of a battery-operated dry erase screen with timer, dry erase markers, eraser and activity sheets\" and belonging to Crayola Properties, Inc.), and it was filed January 12, 2012.
I know I earlier searched for various elements from Legends of the Hidden Temple in TESS and found that many of them were trademarked, but not in reference to the show.