Continuity mistake: The T-1000 has the gun holster on his left side and takes the gun out with his left hand when the guard in the psych ward hits the alarm. A few scenes later when the T-800 (Arnie) asks Sarah to 'come with me if you want to live' the T-1000 walks through the cell doors, the holster is on the right hand side and the gun in his right hand. (01:10:00 - 01:12:00)
Continuity mistake: When the T-1000 throws the driver off the truck and chases John's bike, the buildings on the right are a brown parking lot and a modern white building. In a couple seconds, the truck keeps swapping from being by the middle of the white building or way behind, next to the brown parking lot approaching the white building. The position is inconsistent many times.
Continuity mistake: After the first fight in the steel mill, as the T-800's arm ends up in the gear the black glove on his left hand is torn in many places, revealing parts of the endo-skeleton hand. However, later when the T-800 frees himself from the gear, he is wearing a black glove with no tears on his left hand.
Continuity mistake: When the Terminator smashes the driver's window of the blue station wagon, there is a large section of glass at the top of the door that is stuck in the runner of the door. In the next shot as the Terminator is closing the door, this same section of glass is now missing. Not enough time has passed in the shots for it to disappear and there's no sound of it dropping. (01:13:25)
Continuity mistake: When the helicopter smashes into the back of the police van the front gets completely smashed in and crumples. Next shot is from the side - the helicopter falls to the ground and the front is intact, then smashes to pieces on impact.
Continuity mistake: When Sarah uses her shotgun to shoot the T-1000 in the eye, the first camera angle reveals that the shot has disfigured his head forcing the tissue around the eye to be pushed outwards as a result. In the next shot, when we can see Sarah through the hole as it 'heals', we can see that the head is already in its regular shape as the hole fills.