Does 'By 9:20, Indianapolis Center learned that there were other hijacked aircraft, and began to doubt its initial assumption that American 77 had crashed.' hold a position of neutrality in relation to 'Indianapolis Center learned that another aircraft was hijacked.'
By 9:20, Indianapolis Center learned that there were other hijacked aircraft, and began to doubt its initial assumption that American 77 had crashed.###Indianapolis Center learned that another aircraft was hijacked.