When the T-101 is throwing the T-1000 into the wall at the construction zone near the end of the film the T-1000's hair is longer and ears are not as pointed suggesting the obvious use of a stunt double.
When John is running from the T-1000 through the corridors of the mall, a man yells at him that he's not allowed back there. Later, just before the Terminators begin shooting each other, the man again yells. His lips do not move either time.
In the scene where the T-1000 is torturing Sarah in order to make her call to John, the sound effect that is heard when the T-1000 delivers a left back-kick to the T-800 after being hit with the steel pole is a "sucking" sound rather than that of a hard impact.
John says, "Okay. Time out. Stop the bike." After that, he and the Terminator pull up into an alley and stop. After they stop, you can briefly see the reflection of the boom mic on the mudguard of the motorcycle's front wheel.
When Sarah is approaching Dr. Silberman after she breaks out of her cell, as the camera pans around the corner to show him, a boom is seen above the doorway to the cage area. (This depends on transfer, though, because of the adjustable framing; it's visible on the original DVD and Ultimate Edition DVD, but not on several widescreen laserdiscs. It may be visible in the 4:3 transfer, but that shot is cropped more than opened up and if it is visible it would be in the overscan area.)
(Special Edition) When Sarah Connor is about to take the CPU from The Terminator he says "Do it", look closely at John Connor (Edward Furlong) on the left side of the screen, holding a light - he looks at the camera.
Sarah tells Dr. Silberman that there are 215 bones in the human body. Newborns have around 270 bones, and many of these fuse together during aging, so there is some individual variation in the number of bones in an adult.
Outside the biker bar, as the Terminator scans the motorbikes and then the car, the screen shows an identification of the car as a Plymouth when in actual fact it is a mid-1980s Ford LTD Crown Victoria.
When Sarah is being chased by the attendants as she tries to escape from the hospital, she goes through a glass door that she locks behind her just as the attendants get to the door. As she runs to the next door, the camera dollies back and we can clearly see that the "cell door" has a deadbolt that can be unlocked with a key on either side. Sarah goes through the door, reaches through the bars, and breaks off the key. When the attendants get to the door, they say she "broke it off", but they could have simply reached around and unlocked the deadbolt from the other side.
At 1h 17m 49s Miles Dyson shuts down his computer by just pressing the Enter key. The screen does not show that the computer is in any kind of shutdown page that would allow a single key action like this.
When Miles Dyson is going through the security protocols at Cyberdine, one of the guards asks how Miles's wife and kids are doing. Miles only has one son, Danny. And in Ultimate Cut version of the film, at around 1h22m, we see Dyson has one son and one daughter.
When working on the truck in the desert, the T-800 can be heard panting. Although Reese explains in the first movie that, among other things, the new infiltration units have 'bad breath', it is highly unlikely that the powerful machine such as the terminator would show a signs of fatigue while fixing the mere engine, little less express them via heavy breathing.
When the Terminator's arm gets caught in the gears, he severs it below the elbow to escape and continue fighting the T-1000. Towards the end of the fight, when the Terminator is crawling towards the grenade launcher, the damage is well above the elbow.
When the Terminator gets stabbed in the biker bar, at first it appears to be just above the nipple (and you also see the knife bend). In the close up shot the knife stabs him right on the nipple, then when he walks up to the biker he threw onto the cooker the stab wound is several inches below the nipple.
The T1000 fires rounds into the Terminator's back, but the damage to its jacket disappears when he is thrown through the window. Director James Cameron said the scripting of this sequence at the time of filming was different.
In the mental institute the Terminator pushes a woman by her face, she slides towards the bars then stops by an opening on the right. When the T-1000 slowly walks up to these bars you can see the same opening on the right but the woman has gone, then when the T-1000 starts running and shooting the woman is there again.
When John, Sarah and Terminator take the police car during the escape from the mental clinic, the number on the plate changes in the following shots from 999273 -> 999232 -> 999273 -> 999001 -> 999013 -> 999018.
When the Terminator takes the lever action shotgun away from the bar owner the cocking lever has an oblong opening that closely fits the Terminator's hand. Later, when the Terminator is shooting one-handed while riding the motorcycle the opening of the cocking lever is larger and more rounded, allowing him to twirl it around and cock it at the same time. However, when he and John pick Sarah from the mental hospital the cocking lever changes back to its original oblong shape.
In the shot where the T-1000 drives the truck off the street and into the canal to chase John Connor, the axle breaks down completely when hitting the ground. In the next shot the truck is stable again.
When Terminator smashes the drivers side window of the station wagon some sections of glass remain in the window frame. In the next shot the glass is gone. (There is a scene similar to this in The Terminator.)
When the tanker truck overturns in the foundry, one of the workers activates the alarm. Logically, the alarm would continue sounding for at least several minutes, if not indefinitely. But the alarm is never heard again beyond that shot, which only lasts a few seconds, even though the scene continues in the foundry for at least another ten minutes.
In the tanker truck/pick-up truck chase, after the tanker rams the pick-up and destroys the wooden shelter in the bed, you can see the Terminator turn the steering wheel right but the truck turns left instead
When the Terminator shoots the T-1000 down in the mall corridor, the T-1000 can be seen looking straight at the Terminator with his mouth closed. But in the next shot of him, he is seen looking at the ceiling and his mouth opened.
After John and Tim steel money from the ATM, John says "come on" and runs off without taking the time to complete the transaction and retrieve the ATM (magnetic) card that's still in the machine. In the next shot, John and Tim are running together side by side with the computer neatly wrapped up in the cable with the card that he later uses again at the Cyberdyne building to get the vault key.
The T-1000 riding the police motorcycle crashes through the window, launching itself toward the helicopter. As it crashes through the window, the windshield of the bike comes off, seconds later it reappears on the bike when it falls to the ground.
In the flood control system chase scene, when The Terminator on his bike squeezes past the truck, the truck's left headlight is missing, but in the next shot as The Terminator grabs John the headlight has reappeared.
When Terminator appears it's obvious the trailer was changed because the repair patches and caution sign on the right door have disappeared along with the license plate. Also, with half the left side tires destroyed, the trailer should be leaning at least a little.
When Sarah takes out the power screwdriver to remove the port cover on the Terminator's head (to turn off the "read-only" switch so the Terminator can be switched back to learning mode), he tells her to rotate the locking cylinders counter-clockwise. Sarah tests the screw driver, but it's turning clockwise when she goes to use it.
In the steel foundry toward the end, the Terminator slams a metal bar down through the T1000's shoulder. The T1000 grabs the bar, then spins and kicks the Terminator, sending the metal bar flying out of the Terminator's right hand. In the next scene, the metal bar is seen still embedded in the T1000's body.
In the steel foundry, Sarah shoots the T-1000 several times. He staggers backwards towards two chains strung across an opening in the platform railing. Yet when T-800 shoots T-1000 only one chain is across the opening, the lower chain. Once the T-1000 has fallen neither chain is across the opening as Sarah, John and T-800 approach the opening. No one goes near the break in the railing with chains across, so who unhooked them?
Before Sarah and the T-1000 begin shooting at each other during the SWAT truck/police chopper chase, the two vehicles are seen near a car that loses control and crashes. Later in the chase (before they pass the tanker truck) the same car is seen again, losing control and crashing again.
When the SWAT van crashes through Cyberdyne's front doors into the lobby, it comes to rest with the left rear door open a few inches. When Sarah and John Connor enter it, the van's in a different position and the left rear door is fully open.
Sarah shoots (and hits) the T1000 seven times with the shotgun. The T1000 shows five damage points, and only one of the missing two is explained by its morphing from Sarah's shape into the cop shape. The six shot placements after that morphing process are as follows: 1) chest (right side), 2) chest (center/left, 'heart'), 3) 'stomach', 4) right shoulder (hit point is only seen after next round), 5) right shoulder, high, 6) left shoulder. Possible explanation: First hit point already fully closes 'off screen' while Sarah is still shooting.
In the scene in the steel mill where the T-1000 stabs Sarah Connor in her right shoulder, then raises his right hand to form a metal point aimed between her eyes, there is a cut to a close-up of the T-1000, cocking his head to make a sinister face. His right arm, which should be raised up to make the metal point, is not raised at all. When it cuts back to another close-up of the T-1000, his right arm is raised to make the metal point.
During the liquid nitrogen tanker/pickup truck chase near the end of the film you can see in the close-ups that the Terminator is wearing his black gloves, but when the camera zooms out he's not wearing them on several occasions.
When Sarah is shooting at the T-1000 while the Terminator is backing up the police car, she initially fires 13 shots (more than her pistol can hold). In all subsequent shots during that sequence, she shoots only eight shots before she has to reload.
The T-1000 jumps out of a window on the floor that was just blown up to get onto the helicopter, but he crashes through the unbroken window, when it is clear that all windows on that floor were broken in the blast
During the hallway shootout at Pescadero, Dr. Silberman is present as the T1000 gives chase. Silberman is visible in the background as the T1000 forces open the elevator doors, but when the T800 blasts open the T1000's head, we can see that Dr. Silberman has disappeared.
While driving in the beat-up station wagon, when John is teaching the Terminator to be more casual in his speech (e.g. not saying "Affirmative"), John's right arm moves on and off his raised up knee between the point-of-view cuts.
After the T-800 receives extensive damage from the large gear and the steel girder, whirring motor noises can be heard from the motions of the T-800's body. These noises can no longer be heard after the T-1000 is terminated.
When the terminator is in the bar and asks the biker for the clothes, boots, and bike, you can clearly see someone who works for the bar in the kitchen. Before the other man tries to help the biker you can still see the worker, but when the pool stick is broken on the terminator's neck and the it shows the kitchen again, there is no sign of the worker and there is no way he could have left in half a second.
When the T-1000 is driving the Nitrogen truck down the highway while chasing the terminator and the others in the stolen van, the truck overtakes a car and in the next shot the truck is behind them and there is no sign of a car.
When the Terminator pulls the station wagon out of the garage at the gas station with John in the front seat, the passenger front window is closed. They immediately pull up to pick up Sarah, and the window is down.
When John is explaining to the T-800 that he cannot kill people (because, as John put it "you just can't"), in one shot behind them there is a parked car with some frost or fogging on the front windshield and you briefly see the driver's window is wound up. After he discovers The Terminator obeys basic commands (e.g. standing on one foot), and a jock is grabbed when he tries to help John, you see the same window of the same car (still with some frost on the front windshield) wound down, open or not visible in subsequent shots and with some damage on the opposite side.
At Cyberdyne, the Swat Team Leader says, "OK, drop him," and they start shooting. In the background, on the left-hand side of the screen, one crew member wearing a white T-Shirt walks into shot and exits left. (Widescreen DVD)
When the T-1000 is driving the truck after John on the city street, he plows through two cars stuck in traffic. We're shown a brief shot of the truck approaching them via a camera mounted on the side of the truck. If you look down the road, past the two cars, you can see a special truck with an open back, directly in front of the truck the T-1000 is driving, with a camera and four crew members standing on the back of it.
When the Terminator is backing up the police car through the Pescadero parking lot (right after the car's rear bumper hits the pavement, producing sparks) crewmembers can be seen in the background hiding behind cardboard boxes. (Widescreen DVD only?)
When the T1000 crashes the truck into the bridge, the crash is shown from two angles, one angle from a ledge above and one on the ground, when it cuts to the ground shot, you can see a cameraman briefly appear over the ledge on the upper right corner filming the higher/top shot of the crash.
When John is fleeing up the canal, he is obviously going "upstream". He takes a narrowing, converging fork and the canal gets smaller. When T-800 jumps the bike into the canal, he does it from a point that would be dividing the rushing water rather than converging it, hence, they are now inexplicably going "downstream". A flood control system NEVER diverges the water, it only collects it into bigger and bigger canals toward a common destination.
When the T-1000 crashes the truck into the canal, there is a light pole in the background that has a sign reading "Plummer Ave", however, the concrete bridge has the name "Havenhurst Ave" written on it. This is not a goof because Hayvenhurst, the actual name from the movie, does intersect with Plummer. The signage is correct.
When the Terminator uses the M79 "Thumper" Grenade Launcher to blast open a door at Cyberdine he is only standing about 10 ft away from the door and it explodes magnificently. This is impossible as the 40mm HE (High Explosive) rounds fired from this weapon do not arm themselves until they have traveled 30 meters (approx 90 feet). So the round would have simply dented the door or punched a 40mm size hole in it depending on the material the door was made of.
When John is first escaping up the canal on his motorbike, he continually changes up gears more then the motorcycle he is riding would have. Everytime the camera switches back to him he changes up another gear and then revs it right out while continuing to speed up and doesn't slow down at all to need to be switching gears.
After the T-1000 crashes the tow truck into the canal bridge, we see fuel leaking and a battery cable swinging in the wreckage. The sparking cable is shown to ignite the fuel causing the truck to explode. The tow truck runs on diesel, and diesel wouldn't explode like this.
In the opening scene the semi tractor starts up and immediately drives away. If it had been sitting there for any period of time the driver would have had to wait for the air pressure to build up before he could have released the air brakes and pulled away.
Dyson has to go through what is supposed to be a "clean room" to get to the storage area for the chip and robotic arm. Clean rooms are not used as access routes. Nobody would be allowed to enter the room without proper gear, like the two workers are wearing. They are meant to protect either the workers from hazardous substances, or protect whatever they're working on from contamination. So "civilians" wouldn't be allowed to simply walk through.
John and the the Terminator are changing the starter in Enrique's Ford Bronco, but they are installing the bolts vertically. The Bronco's starter bolts mount horizontally. A Chevrolet would have vertical bolts.
When the T-1000 accesses the police computer at the beginning of the movie, we see that John Connor was born February 28, 1985 and is currently 10 years old. This would mean the film takes place in 1995. Later however, when the T-800 describes the events leading up to Judgment Day, he says Cyberdyne becomes the largest supplier of military computers in three years. That would be 1998, despite the date of Judgment Day given as August 29, 1997 in the same scene.
When you choose the German audio track on the DVD, at the scene at the very beginning, where the T-1000 goes to the police car and checks the entry for John Connor in the police database, the query-screen shows Sarah Connor as his mother, father unknown. In the German audio track they added a acoustic announcement from the computer which says "John Connor... Mutter und Vater unbekannt" which means "John Connor... Mother and father unknown.
John is able to determine the PIN of his stolen bank card after inserting it into the ATM, which does not work that way. The PIN is encoded on the bank card magnetic stripe and is not disclosed by the ATM itself; thus, John should have known the PIN to the stolen bank card before ever inserting it into the ATM, since he had a device to read the magnetic information.
The detonator used at Cyberdine to blow up the labs had a black advanced looking electrical box with a claymore clacker (detonator) affixed on the top of it. The clacker has a black plug on the end that you have to open and connect your blasting caps or in this case the black box to by electrical wire. Throughout multiple shots you can clearly see that there are no wires attached to this and that the plug is also clearly closed.
When the T-1000 first appears he kills the cop and uses his police car. However the cop would have been on a watch with other officers and the T-1000 would have to avoid them for the night as well as not to go to any calls. Also he goes to the foster parents home during the day. If he had not returned the police car at the end of the watch in the morning all of the LAPD would have been looking for him and the car.
When John tells the Terminator, "Now I'm going to go get my mom, and I order you to help me" after the Terminator almost kills the two guys trying to help him, John hands the gun back to the Terminator. John is holding the gun in his bare hand by the barrel which would be too hot as it has just been fired.
When the T-1000 and T-800 fight in the steel factory and the T-800's arm gets pushed into the giant cog, metallic silver paint can be seen on the glove from where the T-1000 pushed it, then when the camera pans away and then back to the arm the paint is gone.
The picture that John's foster mom gives the T-1000 of John to identify him is not actually of him (Edward Furlong) but is of instead of a small boy. This can be seen for example of when the T-100 asks the two girls if they have seen John. Also, the T-1000 would not have been able to identify him in the arcade room this way since it is not a current photo.
At 1h 3min 40s the T-1000 part is thrown from the car. It breaks into a large piece center-frame, and also a much smaller piece to the right. The T-1000 appears to only assimilate the large piece, leaving a small part of himself at the roadside.
When the T-1000 is in the helicopter chasing Sarah, John and T-800, he re-loads his gun. He uses both of his hands to re-load, and there is a third hand clearly visible controlling the joy stick for the helicopter. He simply grew an extra arm to fly the helicopter. In fact, he has four arms in the scene, all of which are clearly focused on in shot.
In the original movie we are told only living tissue or objects encased in living tissue can pass through the time portal, yet T-1000 is made of liquid metal. It is unknown how the T-1000 can travel back but it appears mimetic polli-alloy is an exception to the living tissue rule for time travel. Additionally, why does the T-100 take the shape of a naked man if he is completely metal anyway.
The T-1000 is not supposed to be able to turn itself into moving parts of any kind. But when it kills and replaces the hospital security guard, it has many moving parts before it takes the guard's gun - a keyring full of keys, a nametag with a clip, etc. However, these items are simply mimicked by the T-1000 and are not actually complex objects with moving parts.
At the playground, when Sarah desperately tries to warn people, the shockwave blasts everything (even the charred flesh from the bones) but the little horse on a spring in the background doesn't move at all. Since this is a dream sequence, it doesn't have to obey the laws of nature.
The color of the Terminator's T-shirt changes from black to pale blue/grey overnight as he stands sentry in the abandoned gas station. However, the bullet holes also disappear, which means it's a different shirt, probably one that was at the garage.
When the Terminator is shooting the minigun at police cars in the Cyberdyne building, the ammunition belt does not feed into the gun. In this model (made by General Electric), what appears to be a belt is actually an enclosed feeder.
Sarah Connor tells the doctor she has been good for six months, and he agrees. Shortly before, he tells the students that Sarah stabbed him in the leg with a pen only three weeks ago. However, he may have been agreeing with her to avoid confrontation, or he may have been exaggerating to the students.
When Sarah makes her first shot at Dyson, the computer screen explodes at a different place from the laser sight dot, but between the silencer and the chances she hasn't calibrated precisely, it's not far off.
Terminator explains to young John Connor that the T-1000 can mimic anything it touches. When it mimics the guard in the institution, the only thing it actually touches are the soles of the guard's shoes, as it was hiding as a section of the floor. But touching any part of the object allows the T-1000 to scan the whole object and mimic it. The shoes are not separate objects, but are the bottom part of the guard object. The T-1000 sees the guard as one object (like a toy action figure with its clothes and shoes textured and colored onto it). The T-1000 doesn't have to touch the guard's flesh to be touching the guard. It's not actually mimicking shoes, socks, shirt, pants, underwear, feet with all 5 toes, skin under the clothes, and so on, all separately. It's creating just an action figure with clothing and shoes textured and colored as part of the guard object; just the outward appearance of the guard. But this still doesn't explain how the eyes, hair, keys, uniform, & body shape are mimicked, unless the process relies on optical scanning of the subject, which makes tactile sampling unnecessary and a plot hole.
In the steel mill, T-1000 asks Sarah to call John although he could easily shut her mouth and imitate Sarah's voice.
however earlier in the movie the T-1000 attempted to impersonate Johns foster parents and John saw through the disguise, therefore the T-1000 would rather use the real thing than attempt an imperfect impersonation. It is also explained that in a deleted scene the T-1000's mimicking abilities were hindered by the nitrogen.
In The Terminator the Terminator comes through the time port and his hair is that of the "molding" of all Terminator's. But in T2 when the Terminator comes out of the time "bubble" his hair is the same as after the car wreck scene in the first movie when he puts on the glasses. John may have modified him to look more acceptable to Sarah. It is also possible that Skynet modifies each terminator before sending it into action so that, at least from a distance, they will look different from one another.
When the foster mother Janelle Voight asks her husband Todd for help in getting John to clean his room, Todd discards his cigarette into the ashtray in the room before going out to the garage to confront John. Immediately afterward, Todd is outside as John takes off on the bike, Todd has a partially smoked cigarette in his hand, which he throws on the ground. If you look closely at Todd's hand before he heads outside, he actually flicks ash from his cigarette into the ashtray with his thumb and stands up with the cigarette still in between his fingers.
The T-1000 is liquid metal, and therefore has no need to breathe oxygen or exhale carbon dioxide, but its breath is clearly visible in the cold night air. However in first movie, Kyle Reese tells Sarah that the new terminators (T-101's) have "sweat, bad breath, everything." Since the T-1000 is a newer model to that of the T-101, it is plausible to say that it has "bad breath" too.
(Extreme Edition only) When T-1000 visit the Dyson residence, he overhears on the police radio the dispatch ordering all available units to respond to the Cyberdyne Building and gives the address as "2144 Kramer St". In a later scene, as the police units are responding to the Cyberdyne Building, one of the officers asks the dispatch to repeat the address, she gives the address as "2111 Kramer St". Since the corporation campus is large, there may be several buildings with addresses on that street close enough for a responding officer to find the active location.
When the terminator takes out the swat team in the Cyberdyne lobby, he first uses a pistol before picking up a smoke grenade launcher. After using the pistol he discards it on the floor. Later on at the smelting plant he uses a similar pistol against the T-1000 which could have been picked up outside Cyberdyne from one of the many injured officers or upturned cars or from inside the armory van.
John tells the Terminator how his mom and his dad (Kyle Reese) were together for only one night, but they were together for two - the first night was when they were in the cave and the second when they conceived John Connor together). His mother might not have told him the whole truth, or remembered it accurately by the time he was old enough to hear the story of his conception.
When the T-1000 arrives from the future and steals a police car, he pulls up John Connor's information on the police computer including his home address. Yet inexplicably, the T-1000 doesn't show up there until the next day, after the T-800 had already come and gone.
When the T1000 rides the police motorcycle up the stairs the tires have been changed to knobbies. The motorcycle ridden by the T1000 is a Kawasaki KZ1000P, not a Harley-Davidson as is commonly thought; the Kawasaki with its 1000cc inline-4 engine will obviously sound different from a 45-degree V-twin Harley, but this doesn't explain the transformation of the chassis and wheels.
The Terminator stabs a biker in the shoulder causing the biker to be stuck to the pool table. The knife is not long enough to go through the biker's shoulder and still stick him to the table enough that he would not be able to move at all.
In the Escape from Pescadero scene, when John and Sarah and the Terminator board the elevator, the T-1000 pries open the doors and is about to walk in. The T-101 then blasts his head open with a shotgun. We are briefly shown a clip from a behind the T-1000 camera angle, and before the shot is fired, we can distinctly see the inside of the model head used for the shot. When the shot is finally fired, the head proceeds to pop open to generate the effect of being blown up.
When the Terminator spots John Connor and his pal on the motorcycle from above, he zooms in and freezes an image of John's face to confirm an identity match. The two kids must be travelling at least 30mph on the bike, yet the still image the Terminator takes of John on his moving bike shows his long bangs hanging in front of his face, as if there is no wind blowing against it, suggesting the image was taken separately, and not really while he was riding the bike.
In the Pescadero scene, Sarah runs towards the elevator and stops as the Terminator steps off. When she turns to run around the corner, the striking tape can clearly be seen on the floor. (Visible only in 4:3 home video transfer.)
The computer John uses to take money from the ATM early in the film sports an Atari logo on the screen panel. When he uses it later to bypass Cyberdyne's lock down, a Sony logo is briefly seen on the back side of that same panel.
During the pickup truck/tanker truck chase, just before the tanker truck rear ends the pickup for the first time, you can see the Terminator (driving the pickup) turning the steering wheel back and forth wildly despite the vehicle maintaining its straight-line path.
When the T1000 rides the motorbike up the stairs, tyre marks are left on the floor. If you look carefully in the scene when the swat team go up the same stair case you can see a tire mark on the floor. The swat team went up the stairs long before the T1000 rode up it.
Before the T-1000 runs the Terminator through with the crowbar (in the steel-mill), the Terminator is dragging himself along with one arm. As you see the "stump" move forward and then back, you can see the string pulling it.
When the T-1000 pulls the bar from his abdomen (right after the Terminator cleaves him in half with it), the shadow of the bar is visible on the T-1000's shirt the entire time even when stuck inside him.
When The T-101 is chasing John, he skids in front of a blue Ford, which swerves and two cars, including a yellow Jeep, smash into it. But a closer look shows, the cars are already damaged from previous takes.
Dyson was shot in the left arm. When they went to Cyberdyne he put his left hand into his pants pocket to support it. Later when they were upstairs in the lab he is holding and using a flashlight with his left hand. A moment later his left hand is back in the pocket.
During the escape from Pescadero, there is a shot from outside the car as the T-1000 swings his crow-bar arm through the shattered back window. The background ends abruptly in the upper right corner of the screen, revealing the edge of the rear projection screen used to film the sequence.
When Terminator lifts John Connor off the dirt bike during the canal chase, though it's only a 1.5-second shot, the T-1000 in the background is actually a blue screen image, as evidenced by the difference in contrast and image sharpness between John and Terminator in the foreground, and T-1000 and the truck in the background.
The goof items below may give away important plot points.
At the end of the film they destroy the terminator arm, the chip and the T-800 in order to destroy all evidence they ever existed. However they forget to the remove the T-800's arm that was ripped off in the machine a few scenes earlier. Leaving that arm in the machine leaves evidence that they existed.
The controls which are used to lower the T-101 into the molten steel change position several times. This occurs just before John sees the copied Sarah through to before the T-101 is lowered into the steel (The cable is either wrapped around the bars or hanging).
After the truck explosion, the T-1000 is seen walking towards a police car, wearing a belt with the usual cop accouterments: gun, handcuffs, radio, etc. Not long after that, when the T-1000 morphs from Janelle into the cop, after killing Todd, a pistol can be seen on the cop's hip. In the very next scene the Terminator explains the nature of the T-1000 to John Connor: "It can't form complex machines. Guns and explosives have chemicals, moving parts." However, in the Extreme DVD written commentary (a few different times), it's mentioned that everything on the T-1000's belt is mimicked, and he has to keep stealing weapons and police radios.
After the silent alarm has been tripped at the Cyberdyne building, according to Dyson..."Nothing will open up anywhere now, we have to abort." Later, Dyson and John are able to open the "Vault" with only 2 keys. It seems unlikely that THE most secure room in the building could still be opened with keys after an alarm trip.
When the Terminator shatters the T-1000 to pieces, the room appears to be full with gas nitrogen, while the floor looks like a pool of liquid nitrogen, which is spilling like cascades from the torn truck. However, after just a few seconds, in the whole place there's no trace of the gas any more, not even on the floor, as the T-1000 is able to "meld" back together.
After the T-1000 impales the security guard, Lewis's spasms rock the T-1000's "hand" and spike quite visibly in the first two cuts, but in the side view the hand and the base base of the spike remains still.