Factual error: Throughout the movie, whenever the domes are breached (which happens much too often) it is said that there is only vacuum outside. But Mars has an atmosphere. Its thin and mostly CO2, but it's there.
Suggested correction: While it is not a true vacuum outside the domes, it's around 1% of Earth's atmosphere. The effect of a dome breach would be close enough to a true vacuum to the people affected.
Suggested correction: "Vacuum" is a colloquial way of saying low pressure, just like the 'vacuum' you use to clean the house creates a low pressure to cause suction.
Suggested correction: It's possible human colonization of the planet affected the atmosphere.
If the Martian atmosphere ceased to exist, the sky would be always black, never red as seen in the movie (Mars' sky is actually a butterscotch color during daytime and bluish during twilight).
Factual error: When a person goes out into space, their eyes wouldn't be sucked out, their cheeks puffed, etc. They would have about 10-20 seconds of useful consciousness, when they could get back to a safe area. Even after that, they'd still be alive for about a minute, although unconscious. The only major problem that being in space for about half a minute might cause is rupturing the eardrums and possible blindness (although the eyeballs wouldn't be graphically sucked out). NASA's studies on this go back as far as the 1960's and were used by Stanley Kubrick during the making of 2001: A Space Odyssey. (00:03:50 - 01:43:20)
Factual error: When Quade drills through the hydraulic hose on Benny's mining machine, the pressure indicator on the console drops rapidly and is scaled in "Inches of Mercury Absolute". That scale is normally used only for vacuum, not high pressure hydraulics.
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.