Visible crew/equipment: When the subway train with Annie and Will departs (the train goes to the right side of the screen), there's a close-up of the train. Then, in the lower right corner (during two seconds) you can see a camera, a cameraman and two crew members next to it, reflected on the windows and the shiny surface. (00:46:00)
Factual error: TSA regulations strictly prohibit passengers from leaving an airplane once they have boarded, regardless if the doors are still open, except during an emergency situation. However, Dennis was permitted to leave to look for Will.
Continuity mistake: When Will's mum takes her shoes off she is not wearing stockings. Will starts giving her a foot rub with nothing on her feet. When he goes to get the computer left by the neighbour his mum has stockings on. (00:15:20)
Factual error: Throughout the movie, we see various shots of the Ripley computer system with some sort of fog being pumped around the circuit boards inside. Presuming that this might even be a coolant of some sort, the way in which its being directed and not dispersed would create moisture on the electronics and easily short circuit things.
Factual error: We see Will using a gummy fruit to lift off a fingerprint from a can to then use on the fingerprint reader. This would not be possible due to the fact that the reader used relies on optics to read the ridges on a finger, something the gummy could not reproduce.
Plot hole: When Will is on the airplane talking to his mom, there's a knock at her front door and she says, "There are men in suits here". However, when we see her open the front door, it's covered in thick frosted glass which would make it impossible for her to determine what the people were wearing.
Other mistake: When the guy is playing a computer game in the second scene, he complains to one of his teammates not following orders. He is seen with his hands away from his keyboard, yet his character in the game is moving about. (00:03:00)
Revealing mistake: During the intro sequence where we see a UAV deploying a guided missile, the word "INERT" is seen stenciled on the side of the missile.
