Does 'The most recent hijacking that involved U.S. air traffic controllers, FAA management, and military coordination had occurred in 1993.' stand independently of the premise 'The most recent hijacking that involved three air-traffic related organizations had been in 1993.', neither following nor contradicting it?
The most recent hijacking that involved U.S. air traffic controllers, FAA management, and military coordination had occurred in 1993.###The most recent hijacking that involved three air-traffic related organizations had been in 1993.