Other mistake: After being shot in the air traffic controller's office, the alien disintegrates, but the black residue remaining afterwards is out of position from where the alien disintegrated.
Other mistake: The Invaders' computer announces David Vincent has "sandy" hair, but Vincent's driver's license states he has brown hair. His license also says he has brown eyes, but the actor playing him has blue eyes, and the computer says he's 5' 11", even though one of the Invaders entered the 5' 9" info from his license into the computer.
