Audio problem: When Terminator lifts John off his bike and places him on the chopper, John's cry is heard but his mouth isn't moving.
Sacha
Continuity mistake: When the Terminator's chopper breaks through the gates of the reservoir, they sound as if they crash against the fence, yet a frame later, from the angle in front, the gates are open wide and still.
Sacha
Continuity mistake: John enters the canal, passes by a bridge and pulls over 200 meters ahead. From his POV, the distance from the bridge is merely 50 meters. (00:35:00)
Sacha
Continuity mistake: During the truck scene, when the truck has just come off the bridge, notice the sign on the right hand side says "24 hours." Seconds later the sign seems to have mysteriously disappeared.
Continuity mistake: During the pool fight scene, you can see there's an orange ball next to the upper left pocket. In following shots it's no longer next to it and it has a dark ball in front.
Sacha
Factual error: While escaping Pescadero, Sarah breaks Dr. Silberman's left arm with a baton as he reaches for the phone. Moments later, when Sarah is holding Dr. Silberman "hostage" by sticking the syringe of cleaner fluid, he opens the security doors (which are extremely heavy) with the same left arm. This would be virtually impossible and downright excruciating.
Spencer Crouse
Revealing mistake: In the scene where the Terminator has just broken Sarah out of the hospital and the T-1000 has been shot off the back of the cop car you can see his "metal" arms bending as he rolls across the pavement, and as he gets back to his feet you can see where his real hands are.
dcool84
Continuity mistake: When Sarah Connor throws the keys to a male orderly to distract him, Dr. Silberman is standing right behind him. Two shots later, we see the doctor several feet away. The time lapse between the two shots was only one or two seconds. (00:56:25)
Continuity mistake: At the steel mill, the T-1000 points his finger at Sarah and tells her to call John. The style and position of the loose hairs around her forehead change between frames.
Sacha

Continuity mistake: When John stops his bike at the canal, a supermarket trolley and a flat tire appear behind him. (00:35:00)
Sacha
Chosen answer: He's initially playing Missile Command, then he goes to play After Burner.
envisaged0ne