The narration states that school in Dallas had been let out for the day to enable children to see the President's motorcade. This did not happen, as the school district was debating what to do with early release after the assassination and finally determined that the school buses would run at the regular times that afternoon.
The aircraft identified as "Air Force One" transporting President Kennedy's body and President Johnson to Washington is actually one of the backup aircraft- not 26000, the actual aircraft. This can be determined by the wrong tail number and the absence of the Presidential seal on the forward side of the aircraft.