Other mistake: Before Uncle Owen yells for Luke, if you look very closely, a fly can be seen on the lens (best seen on the special edition release). The fly was removed in the 2019 release.
Plot hole: Further to the comments about the Lunar Lander being useless as a Mars Lander - who is going to believe that three men spent eighteen months crammed into a tiny Lunar Command Module? Not only would they go out of their minds, where would they store the tonnes of water and food they would need in that tiny capsule? How could the Service Module carry enough oxygen or have enough battery power to make the trip?
Other mistake: One visual that has always bothered me that I could not find in your list were the scenes when the mother ship first appears. It's enormous scale appears to dwarf Devil's Tower and the whole surrounding area actually, but when it moves over to the "landing strip" area and begins to rotate 180° (right-side up?), it suddenly seems to shrink to a much smaller size and mass during the slow revolution. On its originally-seen scale above/behind the tower, one would think that either the great ship's outer prongs would have been torn off, or more likely the impromptu landing site and most of Devil's Tower would have been destroyed as the huge craft rotated itself. The visual scales just do not stay consistent throughout the film's climactic final act.
Continuity mistake: In the story titled "Quebec Province 1975", child witch Lucy gets back at her bullying cousin Angela by shrinking her to the size of a mouse. Minutes later, Angela looks up, lifts her hands over her head and begs for mercy. Obviously Lucy is preparing to step on her. But we see Lucy lifting her foot off the floor several seconds after Angela starts begging.
Revealing mistake: At one point in the movie, dumptrucks are sent in to contain the Mighty Peking Man. You can tell that these, like most of the movie are toys.
Visible crew/equipment: During the opening scene when the boat is being pushed ashore you can see the shadow of the boom mike in the water's edge.
Visible crew/equipment: When the camera is pulling back really fast being chased by the people in Africa, its shadows can be seen multiple times on the characters and the walls.
Continuity mistake: The senator is tossed out of the boat and consumed (with the exception of his head) by the monster, and yet the boat is full of blood.
Continuity mistake: The spider lady and the vet go to the rancher's place to burn out the spider hill. While there, a bull runs out and collapses. While the spider lady is talking to the rancher's wife, her hands are by her side. When the camera switches to the wife's point of view, the spider lady's hands are in her coat pockets. When the view switches back, her hands are by her side again.
Suggested correction: You're assuming they travelled from Earth to Mars in the lander alone. The astronauts didn't do this when they went to the moon. The Lunar Lander was attached to the command module during the 3-day journey. When the astronauts reached the moon, they detached the lander from the command module and landed on the surface. It is reasonable to believe the astronauts for Capricorn One did the same thing, except on a much bigger ship for a journey that lasted over a year. We just never saw it.
Mike Lynch
The posting did not refer to the Lunar Lander, it referred to the tiny Lunar Command Module, the only part of the Saturn V that returned to Earth. From 44:00 to 48:08 of the film we see a live broadcast, supposedly from Martian orbit, showing all three astronauts crammed into a Lunar Command Module. The posting is absolutely correct.
This is another Deus ex Machina explanation for a blatant film mistake. The astronauts launched into orbit in a standard Saturn V rocket which could not possibly carry anything like a spacecraft large enough to make the trip to Mars. There is nothing in the film to suggest that there was a "much bigger ship" involved.
They are also shown seated in the tiny Apollo command module, supposedly transmitting messages from orbit around Mars. The posting is absolutely correct.
You're assuming the astronauts were launched in a standard Saturn V rocket, but with all the resources needed for a journey to Mars that took 18 months round trip, NASA would have to send them on a larger rocket to accommodate the required oxygen, water, food, spare parts, supplies, etc. needed to bring them back safely.
Mike Lynch
Did you watch the film? From 1:54 to 2:25 we see an establishing shot of a perfectly ordinary Saturn V rocket on the launch pad. From 6:05 to 6:43 we see all three astronauts strapped into the tiny, Lunar Command Module. As has already been pointed out from 44:00 to 48:08 we see a live broadcast, supposedly from Martian orbit, showing all three astronauts crammed into a Lunar Command Module. There is absolutely no mention of a larger spacecraft and none is ever shown.