Continuity mistake: After the Endoskeleton emerges from the diesel fire look at his teeth. They're clearly metallic when he stands up and chases after Sarah and Kyle, then when he enters the factory his teeth are white enamel. Then when he's fighting with Kyle they're metal again and finally they turn white after he's blown apart. (01:31:05 - 01:34:20)
Continuity mistake: In the factory, when Reese yells at Sarah to run and then turns and starts bashing at the Endoskeleton with his metal pole, if you watch carefully you can see that his fourth blow snaps one of the head supports. Yet we see a closeup of the head during his fifth blow, and the support is fixed again. (01:31:14)
Visible crew/equipment: When Sarah and Kyle have run into the factory, the Terminator is breaking through the armour plated door. As the Terminator comes through you can clearly see the two operator guys crouching behind the model. (01:32:45)
Visible crew/equipment: As the Terminator moves his right arm whilst in the press, you can see a crew member, behind the Terminator, move in the area of the picture where its arm was. (01:34:05)
Revealing mistake: After Reese finishes battering the Terminator with the pipe, the Terminator strikes back at him. Just before the camera angle changes to show us the pipe dropping on the floor, we get a close up of Reese's face. It is a stunt double, not Michael Biehn. (01:35:10)
Continuity mistake: When the Terminator is crawling after Sarah Connor at the end of the film there is a close up of the endo-skeleton and the hydraulic cables from around his shoulders are missing. (01:37:15)
Visible crew/equipment: At the end, when Sarah puts her glasses on, a light screen is reflected in them. (01:38:45)
Revealing mistake: At the end of the film, at the split second we see the ambulance workers zip up Reese in the bodybag, his right eyelid flinches a bit. (01:39:45)
Revealing mistake: "Dead" Kyle Reese is still breathing. (01:39:45)
Revealing mistake: There is a shot from the Terminator's POV, before he rams the blue car with the semi truck, in which you can see that the car is already damaged. No slow-mo is required to see this, but it is a blink-and-you'll-miss-it shot.
Visible crew/equipment: In the police station, you see all the police officers running to get the automatic weapons. There is one shot where a red dot is seen to be following one officer (and it's sometimes on his back). No cops are facing the back of this cop, the Terminator is not around this part of the station, so it must be off the camera.
Revealing mistake: When the Terminator goes into the Alamo Gun Store scene of the famous "Uzi 9 millimeter" quote, the man turns to get something off the shelf, and Arnold takes a shell out of the box on the counter. It is an already fired shell - you can tell by the dimple in the center of the primer.
Character mistake: When Kyle steals the police officer's gun and asks him what the date is, the officer replies "12th, May, Thursday". The film is set in 1984. May 12th, 1984 was a Saturday.
Factual error: Sarah and Lieutenant Traxler both state that Tech Noir, the club Sarah is in, is on Pico Boulevard. After the gun battle inside the club, Sarah leaves with Kyle and they run a short distance down the alley behind the club before getting into a car. The Terminator jumps on and falls off as soon as the car is out of the alley. When the cop calls it in, though, he says he needs an ambulance at 7th and Broadway. Even assuming Tech Noir was on the corner of Pico and Broadway, that is still about 3/4 of a mile away from 7th and Broadway, so there is no way that was the intersection just outside the alley.
Continuity mistake: Two large railings can be seen curving around the building corners when the cops arrive at the alleyway to pursue Reese. Those railings weren't present in the shot preceding Reese's arrival; the cops pulling up was filmed in a separate alleyway.
Revealing mistake: In the shot of the Terminator skidding down the street after being rammed by the pick-up, it is a dummy. It's even missing a hand.
Audio problem: In every version of the film from the 2001 DVD onward, Kyle's shotgun has two completely different firing sounds in separate scenes. In the parking garage shootout, it sounds muffled, whereas it didn't sound that way in Tech Noir.
Continuity mistake: When the Terminator arrives at the first Sarah Connor's house, the address number is "14239", even though in the phonebook it is listed as "1823" (or "2816" or "309").
Character mistake: In the final scene at the Mexican gas station there's a sign that says "cigaros" instead of "cigarros," which means "cigars" in Spanish.
Continuity mistake: When Arnie says "I'll be back" and leaves the police station he throws both the doors open as he leaves one of them falls back into place but the other one stays open. When he drives his car through the window both doors are closed.
Chosen answer: Since terminators cannot self-terminate, only one very likely possibility comes to mind: it would have hidden itself away somewhere known to have remained undisturbed in the years between the termination of Sarah Connor and the start of the war, at which point it would rejoin the war effort.
Phixius ★