Revealing mistake: When the Hudson Ferry captain casts off the large label that reads "Hudson Ferry" is on his left side of his jacket. However, in the exterior shot as he looks out the window at the whirlpool, the label is on his right side. This shot was flipped, and amusingly, the CGI guys actually retouched the words "Hudson Ferry" so it wouldn't read backwards. (01:02:25)
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.
Revealing mistake: Mirrors were used to make the corridors appear longer, early in the film when Brett is complaining to Parker about the way they are treated by the company you can see their reflections in the mirror behind them as they walk down the corridor. It's only for a second as they are moving off camera but you can see them in their white overalls.
Revealing mistake: When Sarah is making her way to the baby Stego, just before she gets on her belly and crawls closer to it, you can see the kneepads she has on.
Revealing mistake: As Carlos is giving his final goodbyes to Claire you can see in the background automobiles driving down the freeway. Shouldn't these roads be empty rather than having what seems to be a thriving highway? (01:10:00)
Revealing mistake: There is a shot right after the first time the clerics are entering the city from the nethers that you see an APC patrolling the wall road above the entrance. In that shot two shadows are being cast on the road. As the CGI APC passes through them they simply don't cast a shadow on it as they should. (00:08:40)
Revealing mistake: Near the end, as they approach LAX, the woman says there is nobody on the ground, that it's just the same as Bangor, but actually you can see a few cars moving on the ground.
Revealing mistake: Mac and Dillon go after the Predator. The Predator is sitting in a tree, and Mac points him out to Dillon. They both agree that they see it and take position. Mac crawls underneath the alien and is killed by his laser. The Predator then sees Dillon and lasers his arm off. Dillon's arm falls to the ground with the gun firing. Quickly Dillon turns and reaches for the machine gun around his neck. When he turns you clearly see his bloody right stump and his right arm sticking out the bottom of his jacket. [Note: As far as I can work out, this has been cunningly edited out of the UK DVD version].
Revealing mistake: When Fin decides to help the kids on the bus and says, "Water's rising, I'm gonna go up to the bridge and rappel down," two shots later the camera zooms in on Fin's car up on the bridge, but the problem is that this shot is shown in reverse - all the vehicles in both lanes are going backwards.