Continuity mistake: In the scene where Maggie goes to the restaurant with Bob, he offers her the case where the weapon is. Bob says, 'It's loaded'. Close inspection shows the clip chamber is empty (not loaded), and a cartridge clip is positioned beside the weapon in its tailored slot in the custom case. Maggie closes the case and says, 'I don't understand.' After Bob explains what she is to do, then leaves, Maggie opens the case again and suddenly there's a clip in the weapon (loaded) and another one beside it. The weapon was not loaded when she looked the first time.
Continuity mistake: You can clearly see the blood packet underneath his head right before he hits the ground.
Continuity mistake: In the hotel scene where Darby calls Gavin to give him the instructions to meet her the next day, he eats one of the chocolates on his pillow and throws it down. They show a close up of the chocolates. After Khamel murders Gavin, he walks to the bed, pulls the recording device and eats one of the chocolates. They are now in a different spot on the bed. (00:59:55 - 01:00:25)
Revealing mistake: After Naomi is thrown from her balcony in the beginning, the blood on her face has beaded down her face and is staining her blouse. This is impossible being that the injuries she received happened less than a second before and she landed face down after going through the glass, so the blood couldn't have ran down her face in that direction.
Visible crew/equipment: You can see a rope visible when Charlie is hanging from the hotel roof.
Continuity mistake: In the scene where Gard telepathically fights an alien, you see his nose bleeding. Then the alien explodes, and in the next shot of Gard's face, the blood under his nose has vanished, only to return in the next shot of his face.
Plot hole: There is a guard stationed in the time lock vault without oxygen. Also, if the vault was supposed to be that secure, why were there simple bars protecting the back entrance?
Plot hole: Andy is interrogated by the detective after the latest rape, as evidence in this one points to him. Problem is, the cop mentions that all the victims had visited Andy's office before their attacks. In real life, with information like that, he would have been a suspect and subject to questioning from the very first incident.
Deliberate mistake: At the end of the film its revealed all the murders were a hoax and everyone was in on the plan to set up Rex (Lee Majors). Why then exactly were Rachel (Vanessa Angel) and Patrice (Adrian Paul) talking together and pretending like they were trying to find the killer. In one of the scenes Rachel believes she has caught a photo of one of the men who she thought might be a killer and is showing Patrice, but Rex wasn't anywhere around. Therefore why were they pretending to find a killer or keep up the illusion whilst Rex wasn't around?