Continuity mistake: In the police car after escaping from the T-1000, John's hair is moving to the left because of the wind. When the angle changes to a POV from the driver's seat, right when he says "I had to get you out of the place", his hair is moving wildly to the right, then a frame later, from a new angle, it's back to the previous mild movement to the opposite side.
Continuity mistake: John Connor comes out of the parking lot and appears right in the middle of the truck's lane, making the driver swerve to his left. From a close-up, the driver turns the wheel and straightens the truck and keeps on driving, but the following wide angle shows the truck swerved and the driver straightening it again.
Continuity mistake: When John and Sarah are in the pick-up truck trying to outrun the overturned liquid nitrogen tanker, the driver's door of the pick-up truck goes from swinging open, to closed, to open again between shots.
Continuity mistake: During the escape from Pescendaro, the Terminator shoots the T-1000's head and the T-1000's head splits apart. When this happens Doctor Silberman can be seen nervously in the background. The shot then cuts to the Terminator, John and Sarah and then the shot cuts back to the T-1000. However, when the shot cuts back to the T-1000, Doctor Silberman isn't there any more. (01:00:00)
Revealing mistake: When the cop by the vending machine is about to be killed by the T-1000, the back shot of him reveals he's been replaced by an obvious mannequin. His perfectly trimmed hair along the nape is now long and messy, and a long stitch appears along his sideburn and down to the neck.