Continuity mistake: When Harry, dressed as an overseas pilot, enters the aeroplane during the hijack scene, one of the hijackers draws his gun right in front of Harry when he says "Good afternoon". In the next scene, the gun is further away from Harry than it was in the previous shot.
Continuity mistake: When Lt. Briggs is being interviewed after the swimming pool massacre, we see a close up of Briggs and there is a man with a moustache next to him. But when we cut to the next shot where Briggs is on television at Carol McCoy's house, the man with a moustache has suddenly disappeared.
Continuity mistake: After one of the cars escapes from Palancio's hideout, we get a view from the driver's seat and Harry fires a bullet into the windscreen and the car is heading directly for an office. In the next scene, the car is much further away from the office than it was in the previous shot.
Chosen answer: The error didn't necessarily start with the makers of the credits. It could have crept into the process at any point. Whoever typed up the names to give them to the technicians who made the credits could have misspelled the name.