Revealing mistake: When David enters the food robot to escape, he makes a left at a cop car with the license plate 11385. A few moments later, he passes the same exact car going in the other direction. (00:41:40)
Revealing mistake: In the scene where Max challenges David to navigate the ship on his own, fingers are seen controlling the Puckmarin's movements at one point. (01:04:05)
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.
Revealing mistake: When introduced to what David calls "Popcorn", the wires moving the puppet are visible.
Answer: The only people with different young and old actors were Jeff and Carolyn. The scene with young Carolyn would have been after he got back from the future and was filmed, but cut for pacing reasons.
LorgSkyegon