Visible crew/equipment: Special effect projectors and strobe lights can be seen in a reflection on Max as the ship is descending towards the bay - moments before blasting into hyperspace to return David to his home in 1978. (01:22:15)
Continuity mistake: Throughout the film, especially inside the spaceship when its flying, the boy's hair goes from short to long in fact he is at least 6 months to a year older facially too.
Continuity mistake: As David and the ship are leaving the NASA hanger, the straps that are holding the ship down start to break. From the shot outside the ship, you can plainly see the straps hanging on the front off the ship, but from inside the ship looking out the front "viewscreen" you see a clear picture, with no straps obstructing the view.
Revealing mistake: Many times during the movie, when there is a close-up of the puckmarin, tiny wires can usually be seen attached to its arms.
Continuity mistake: After David has relieved himself, he and Max start a heated conversation about why the computer hadn't returned David back to his own time; a herd of cows grazes nearby. Towards the end of the debate, a cow can be seen near the ship's hatch in a close-up; in a wide shot, the cow is gone; and in a second close-up, the cow stands near the hatch again.
Factual error: When the alien craft speeds away from the NASA base, its slipstream tears off the roof of a small booth. But the wake also should sweep the people in its flight path down to the ground; it is too close for that not to happen.
Factual error: When the ship goes straight up 20 miles, the ship is in space with the curvature of the Earth and atmostphere visible. 20 miles is just over 100,000 feet. He would have to have gone over 50 miles up to reach space.
Continuity mistake: When David is in the ship at the NASA hanger, just as Dr. Farraday asks him to get out of the ship, the door closes. From outside the ship, the interior is pitch black, but in the very next shot from inside the ship, it is lit up from the front "viewscreen" and various lights on the wall, which should have been visible as the door closed.
Visible crew/equipment: When David starts to navigate the ship, watch the metal wall behind him, and you will be able to see the camera crew and realize that the spaceship is a prop by seeing a black wall behind the camera.
Continuity mistake: When David is using a map and eating a candy bar, one shot shows it bitten into. The next shot shows it whole, and the next shows it bitten into again.
Continuity mistake: When the car full of "geeks" takes off from the intersection, the white semi that was approaching should have met and passed the car at the speed it was travelling, but disappears.
Revealing mistake: When introduced to what David calls "Popcorn", the wires moving the puppet are visible.
Other mistake: When examining the craft in the hangar, it's reported there are no seams or any way in or out, but when the camera focuses on the man's hand, you can see the seam where the hatchway will be.
Continuity mistake: When David goes to his room early in the movie (in 1978), if you look closely you can pick up what looks like a football card wrapper on the shelf on the left side of his room, near the white helmet and behind David's Dad. Comparing to known wrappers, this one was issued in 1985.
Answer: According to IMDB, Paul Mall is just another one of his names people know him by.
Sir William