Continuity mistake: At Hoover Dam, when the soldiers salute Keller the clock reads 10:00, then as Keller, the soldiers, Maggie and Glen walk away in the background, when Simmons tells Sam that they got off to a bad start the clock reads 11:35, and next shot when Banacheck interrupts it reads 11:43. Also when Simmons talks to Mikaela and Sam the word "Nevada" is gone and it only reads "Time" under the clock. Then when Banacheck says, "Come with me, we'll talk about your car," the word "Nevada" is back under the clock.
Continuity mistake: After Gerry gets smacked in the face by the 'broken' suspender clasp, we see the silver clasp land under the dresser. Yet, when he's moaning and lifting his leg to get onto the bed, we can actually see the clasp still intact on the front suspender that came loose, which is dangling right behind him (just look between his legs). Of course, in the next shot, that clasp is gone. Since the silver clasp is one of the plot points, this is bizarre to say the least.
Continuity mistake: When John and Catherine are in the hangar at the runway, the Cessna's tail number is N3035C. When the plane is shown in the air, the number is N3973F. When they land, the tail number has changed back to N3035C.
Continuity mistake: In the bedroom scene the girl is holding a clear cup full of beer. The camera goes off her and when it comes back she is holding a blue cup. The camera goes back off her then on her and the cup is clear again.
Continuity mistake: When Sam is in his bedroom, after he finds the Cube sliver it falls and dramatically burns a hole through the floor into the kitchen. But Sam's bedroom is over the living room (there is nothing on the ground floor below Sam's elevated bathroom, and in the first movie Jazz hides in this open space), and the kitchen is actually located between the den and dining room, at the other end of the house. If they were to follow the actual floor plan of the house, the Cube sliver would have landed in the area of the piano in the living room, but where would the fun have been in that?
Other mistake: When devising the plan to retrieve Watney, it is mentioned that the Hermes crew have had to lash together all the webbing on board to make the longest possible tether. When this tether is used, there is no evidence of any lashing together or other extensions or modifications to lengthen it. The tether is one continuous length and is stored on a reel that was designed for the length of tether gathered on it.
New this month Visible crew/equipment: Towards the beginning of the film we see the convoy driving to Ciudad Juárez on the highway. In the reflection of the last car one can see the Russian Arm used to film the vehicles.
Factual error: In different shots of the movie you see the characters warming their hands with their breath; which in real life would be an absolute no go, as the humidity of the breath will make the hands wet and colder/frozen. Also, when most characters reached the "death zone" they were not out of breath and spoke sentences too long for the shortage of oxygen on that altitude.