8. Why Do They Forget To Throw The New T-800's Arm Into The Molten Metal Pit At The End Of Terminator 2: Judgment Day?
One of the most spectacular action sequences of all time comes at the end of Terminator 2: Judgment Day - having stolen the CPU and arm used by Cyberdyne Systems to reverse engineer their technology, the Connors and the T-800 take them to a steel works to dispose of them. All well and good - after a great elongated battle with the seemingly unstoppable T-1000 they throw the arm and microchip on top of their pursuer in the molten metal, destroying all traces of the terminator from the present day. Except someone forgot to go back and get the other T-800's arm, still stuck in one of the machines in the steel works after Arnie battled with the T-1000. You could argue that this arm then went on to build the robot army, but since the sequels in the franchise don't suggest this you can put it down to a plot hole instead.
