Continuity mistake: The American flag on the raft moves from shot to shot. That can't happen, because the raft was tethered to the spaceship while Taylor was throwing the supplies down. (00:10:15)
Continuity mistake: After the ship has sunk, Taylor, Landon and Dodge make camp on some rocks. In the shot where Taylor says "Dodge, run your soil test. Got your sensors? Geiger counter?" in the background is the life raft used when they escaped the ship. The raft is resting on some rocks that are bright colored. In the next shot, in a shot of Landon the rocks the lift raft is resting on are all dark colored. The raft has also moved closer to the water. (00:12:35)
Continuity mistake: When Taylor and Landon discuss Stewart's death on the rocks, their hair goes from being blown in the wind to resting still between shots. (00:13:00)
Continuity mistake: When the three are doing water check, the wide angles show Landon sitting in the sun, but the closer angles show Landon sitting in the shade. (00:17:15)
Continuity mistake: When Taylor, Landon and Dodge do water check, during the shot where Landon says "Thunder and lightning, no rain", Landon is looking down on the ground. In the next shot, as Landon finishes the line with "If we could just get a fix", he is suddenly looking upwards. (00:17:35)
Continuity mistake: Taylor, Landon and Dodge go for a dip in the river and they get wet. The humans then take their stuff, so they get out of the river and they are all mostly dry (still a bit damp, but less dry than they were before). (00:25:40 - 00:27:25)
Continuity mistake: When Taylor, Landon and Dodge discover the humans, when Dodge says "Blessed are the vegetarians", both Taylor and Dodge are standing even with each other and Landon is standing about an inch or two behind Taylor and Dodge. In the next shot, Landon and Dodge are standing even with each other and Taylor is standing almost a foot away from Landon and Dodge. (00:29:00)
Continuity mistake: After Dodge is killed, Taylor finds him in the field and holds him. Dodge's head changes position between shots. (00:32:40)
Continuity mistake: When Julius starts hitting Taylor in his cell, Taylor drops the notepad and pen he is holding and it lands about 4-5 inches away from him. A couple of shots later, the notepad is suddenly an inch away from Taylor without being touched. (00:45:10)
Continuity mistake: When Zira looks at the "My name is Taylor" on the notepad she says "Get me a collar and leash." The shot then cuts to Taylor in the cell. In this shot, he has a few strands of hay along his arm, but in the reverse angle, there's hardly any hay on along his arm at all. (00:45:35)
Continuity mistake: When Taylor is trying to describe where he came from to Zira and Cornelius, he has Cornelius hold up a map. Cornelius holds the left side and Taylor holds up the right. As Zira says "You fell into the water here?", the map is slanted to the side. In the next shot, Taylor suddenly isn't holding the right side of the map and the map is more levelled out. (00:48:20)
Continuity mistake: When Julius arrives to escape Taylor from his cell, he gives the guard a note who has a cigar in his mouth. When Julius tackles the guard, the size of the cigar differs between shots. (01:18:50)
Continuity mistake: After Lucius knocks out the guard, Lucius then ties the guard to the cell bars. In the shot where Lucius says "I'm Doctor Zira's nephew. This abduction was her idea", it can be noticed the fingers on the guard's right hand are resting freely. Then as Taylor says "Get me out of this", the fingers on the guard's right hand are almost clenched together. (01:19:00)
Continuity mistake: When Lucius releases Taylor from his cell after knocking out Julius' the guard, his hands are shown to be tied above the horizontal lining along the cell. Then as Lucius says "We've got to move fast", the guard's hands are now tied below the horizontal lining along the cell. (01:19:05)
Continuity mistake: Towards the end of the movie when Taylor, Cornelius, Zira, and Nova are about to enter the cave, Zaius arrives with his crew. Taylor comes running back taking a few shots at the soldiers then he points his gun at Zaius. In a frontal shot you will notice the gun he is pointing has a strap on it tucked under his left hand as he is aiming. The scene goes to a rear shot of Taylor in the foreground and Zaius in the background on the beach. Look close at the gun Taylor is pointing and you will see the strap hanging free. As the scene returns to a frontal shot you will see the strap is tucked under his left hand again. (01:31:27)
Continuity mistake: When Taylor ties Doctor Zaius up to the log, shots from behind Zaius show the rope at the top of the log just above Zaius' head to be wrapped around the log only twice. Shots from in front of Zaius show the rope to be wrapped tightly a dozen times around the log. (01:37:35)
Continuity mistake: After the apes have blown up the cave, Taylor and Nova are shown riding away on a horse. In a close-up, Taylor looks at Nova and places his hand on Nova's cheek, but in the reverse angle he suddenly doesn't have his hand on her cheek and he is now looking straight forward. (01:44:30)
Continuity mistake: When the spaceship first springs a leak and begins to sink, the interior shots show it tilting to starboard; Taylor falls against the starboard bulkhead and the other two survivors need to brace themselves from slipping. All of the exterior shots of the ship show it level from port to starboard.
Continuity mistake: The first exterior shots of the spacecraft in the desert lake show the spaceship's hatch door already gone... before the astronauts blow it off with an explosive charge minutes later in the movie.
Continuity mistake: At the end of the movie when Taylor and the woman find the ancient ruins of the Statue of Liberty, their distance from the statue seems to change between shots. In the first shot (when it only shows them and the torch) they seem to be almost next to it. In the next shot (when it only shows them and the crown) they are farther away. And in the last shot (when it shows Taylor kneeling from behind and the full torso of the statue) he is even farther away from it.
Chosen answer: Dr. Zaius did know the true history of man and ape, but he deliberately hid the truth from the other apes. For Zaius (and other high-ranking apes who were guarding the secret), it would be shameful and demoralizing to ever admit that humans were far superior to apes in the past and that they could, potentially, conquer the apes. In more than one scene (such as the paper airplane scene in the first film), we see Zaius obviously frustrated that Taylor's very existence threatens to expose the truth.
Charles Austin Miller