Revealing mistake: When the Bronco is underwater at the end of the movie, Claire's hands are tied to the steering wheel. Doug rips the steering wheel off. Anyone who has worked on cars knows you need a puller to get a steering wheel off. Also, the steering wheel is gone when Claire swims to the surface.
Plot hole: Julia dies in the underwater escape trick tank because the axe couldn't get her out in time. However, if she was able to open the lid from inside the tank, get up, over, and down, then close the lid (all quickly, silently, and without assistance) when the trick goes properly, then there is no reason that the four men standing around could not have simply lifted the lid, either acting a key in the fake padlock to preserve the trick, or using a key if it's real. At this point she could have gotten her head above water and draped her hands over the side of the tank to stay up. That done, the crisis is over, and she must only wait to calm down enough to get herself down, or be assisted. Cutter built the tank, so he knew how strong the glass was. The only explanation for using the axe was to allow Julia's death, thus advancing the plot.Phixius
Other mistake: When Joey Lawrence gets his hand cut off by the human, he wakes up to find his arm where his hand used to be wrapped in some kind of black cloth. It's obviously his hand that is wrapped up because the wrap sticks out too far to be only wrapping his wrist. Plus it is also bulky which gives away the hand underneath.
Factual error: When Izzy urges Tom to watch through the telescope on the rooftop, he just looks and sees the nebula. From space observations done by myself, I know that the earth rotation is so fast that even for this amount of time, a manual correction must be done to center the view again.
Continuity mistake: In the scene where Dean Cain's character and the girl are chained together with the shackles. Dean leaps through the window and crashes to the floor. The girl then jumps through the window and neither of them is wearing shackles. There was no cut, and no indication they had a key.Jason Hoffman