Factual error: Martian sky is very inaccurate in the movie. It is depicted as much darker and redder than it would be in real life (Mars' sky is a butterscotch color during daytime, bluish at sunrise/sunset and far brighter than in the movie). Also, both of Mars' moons are very small, asteroid-like bodies and would appear as tinny star-like points of light to an observer on the surface of the planet.
Revealing mistake: When Richter's arms get cut off and he falls down the elevator shaft to his death, you can very obviously see the outlines of his real arms inside his shirt when his leather jacket flies up as he falls.
Continuity mistake: When the man delivering the briefcase calls Quaid and tells him to go to the window, you see on the screen he turns to look to his side, but when Quaid goes to the window the man on the phone is still looking straight and then is seen turning to his side again.
Continuity mistake: When Quaid first arrives at The Last Resort, he hands Benny a tip and walks in through the front doors. In a front shot behind him is the head of a man outside who wasn't there a moment before when Quaid walked in.
Other mistake: When Quaid goes through the x-ray machine the first time, the person behind the man with the dog isn't shown to be carrying anything (there's no purple object shown). But then later the purple object is seen.
Suggested correction: Could simply be someone else with an item passing the person without any. He was walking very slow and certainly 1 person passed him, could be another one did as well.
Two people would have had to pass him and there's nothing to indicate 2 additional people were walking that much faster than him, or close to him.
They were off camera before. 1 person definitely did pass him so a second person doing the same is not unlikely.
They weren't off screen long enough.
I've seen this part multiple times. Who you see behind Quaid before entering the machine is first a woman with a handbag, then a man with mustache and case, then a blind man with a dog, after him a woman with a handbag again and more people. Now, the man with the mustache and case and the second woman with the handbag probably paused before entering the machine because we don't see them when Quaid passes, only the first woman with a bag, then a blind man with a dog and then a man with nothing. So both must have then sped up and then passed the man holding nothing. You see them walking faster than the others too. Not illogical when people are rushing to work or home either.
Continuity mistake: In the apartment, Lori grabs a knife, and after the first slice, switches the knife to her right hand. After the second slice, the knife can be seen midair as she tosses it from left to right again.
Suggested correction: It's not being shown tossed from right to left, you just see her spin the knife in the air to hold it in a different position.
Other mistake: After Arnold kills Harry and his gang at the beginning, how did that blood splatter get on the wall behind him to his right? He shot the henchman standing in that position from the back and the other who was shot was shot standing to the left side of the wall. So there is no explanation why the splatter is there.
Continuity mistake: When Quaid takes off his old woman disguise and throws the head to a soldier who catches it, the close-up shows that he's holding it beneath the ears. In the wide shot, he's holding it from behind the skull.
Revealing mistake: Sharon Stone gets shot dead, but she moves afterwards.
Continuity mistake: After Edgemar lets Lori in and closes the door, a moment later the door is open in the mirror's reflection.
Continuity mistake: As Quaid copies the name Melina on the paper, the writing is in heavy black ink. When he leaves the counter the writing is very light, nearly non existent.
Plot hole: It's revealed by Cohagen that he had everything set up for Quaid to get to Quato including convincing Quaid that Benny was an ally but there's no way Cohagen could have known that Quaid would have chosen the other taxi driver instead of Benny. So if Quaid had picked someone else or even decided to walk to where he was going Cohagen wouldn't have got anywhere in drawing Cuato out.
Suggested correction: Simple, every cab driver there was under his control. Didn't matter who was picked. Ever see a movie where everyone in a restaurant turns out to be an agent, or that scene in John Wick with everyone in the park.
