Revealing mistake: When people disappear because of the time paradox, the background changes. This is especially noticeable when Johnson disappears, watch the lights on the panel behind her go out. (00:13:35)
Continuity mistake: When the first sterilisation unit is hunting for prey in the desert, it fires a few shells towards the destroyed caravan. Yet we never hear explosions or see any fireballs in the next shot. It also appears that the robot was firing at nothing. (00:16:05)
Continuity mistake: When the sterilisation unit finds Nicholas in the desert, when he stands up and the robot is looking at him, there is a lot of debris around him. When he says 'cease operation' the debris disappears. The rock face behind him changes position as well. (00:16:35)
Plot hole: When the first sterilisation unit encounters Nicholas in the desert, he commands it to 'cease operation' and it becomes harmless. There was no reason why he couldn't have used the same command later on in the movie when he encountered deadly robots, particularly when one was teleported to the lab. (00:16:40)
Continuity mistake: When Gunney fires the large cannon at the first sterilisation unit, from the frontal view it is obvious that the explosion has fallen well short of the robot. Yet from the side, it appears to have been a direct hit. (00:21:10)
Revealing mistake: When the team are heading back to base and we see the skyline for the first time, it's obviously a painting projected onto a blue screen. You can see the line where the set and the screen meet. There is also a white line running across the bottom of the screen. (00:24:50)
Deliberate mistake: When the recon team head out of the base they encounter a robot. But it is a probe droid, distinguishable by the lack of a cannon on its right arm. The only probe droid that the lab sent out self-destructed back in the 1970s, the rest were all sterilisation units. (00:39:05)
Continuity mistake: When Natasha is shot by the robot, the shot travels right through her, like a normal bullet would. Yet in every other scene when the robots use their pulse cannons, including when Rasheed dies, the shot always causes an explosion. With Natasha, no explosion was seen or heard. (01:21:30)