Factual error: When Arnold is done shooting at the cops in the graveyard scene, there are birds singing in the background. No way that any birds would be left in that area (not to mention singing) after at least 15 machine guns have been firing for more than 2 consecutive minutes, not to mention the cop car exploding. (00:55:50)
Factual error: All over the particle accelerator you can read about the dangerous magnetic fields that are caused by it. the radiation that is created by the accelerated particles is mentioned nowhere although there is no possibility to find a wall without radiation warnings in a science lab with a real accelerator.
Factual error: When the T-X is driving the crane and swinging the Terminator around, that is mechanically impossible. All mobile cranes are designed to run only when they are in neutral. The T-X would have burned out the hydraulic pump within seconds. (00:33:50)