Continuity mistake: In the scene after the prison break, we see Richards, Weiss and Laughlin walking through the city. On the big television screen there is a commercial for The Running Man game show. The footage they feature on the commercial is footage from the episode Richards is in. How could they show footage from that episode if it has not taken place yet?
Continuity mistake: In the fight scene where Arnold is fighting the hockey goalie, he gets cut on barbed wire and leaves a bloody tear on the chest of his fancy spandex bodysuit. In the very next scene the suit is clean and the rip is gone.
Continuity mistake: The film opens with Arnie in a helicopter, refusing to fire on "helpless people." At the film's climax, when the (undoctored) film of this event is screened, it is changed to "helpless human beings."
Continuity mistake: In the scene with Buzzsaw, after Richards ties the rope around a metal spike, Buzzsaw flies off his bike and lands face down. When Richards approaches Buzzsaw, he is still face down. Then when Richards starts to reach down to grab the chainsaw, Buzzsaw's arm comes up to choke Richards and he is now lying on his back. Richards would have reacted quicker, since Buzzsaw would have had to flip over on his back to grab Richards.
Continuity mistake: When Killian is looking through the computer for the next contestant, the last person they show is Mackenzie Spike. We see his personal info (occupation, hobbies, eye color, resident), the numbers pop up, and then it shows a completely different set of personal info (despite being the same guy with the same prisoner number).
Continuity mistake: As Richards and Buzzsaw are trying to overpower each other with the saw between them, the angle of the saw changes between shots. First, it's over Ben's left shoulder, then over his right as Buzzsaw talks. Also, when Buzzsaw talks, you hear the saw revving, but the chain isn't moving.
Continuity mistake: When people are walking into the building before you see where Amber lives, she is wearing her white robe and watches the news report that Richards shot the people at the airport at 'point blank range'. She says, "But that's not true!" and you can see Richards walking into the building wearing his work clothes at the bottom left corner. That scene had already been seen when Richards went to find his brother Edward, who lived in Amber's room previously. (00:27:53)
Continuity mistake: As Fireball deflects the barrel Richards throws at him, his flight jets disappear and reappear between shots.
Continuity mistake: When Richards is overpowered and pulled out of the pilot's seat in the chopper, his communications earpiece is still attached to him. As he's slammed into the back wall, it's suddenly gone.
Continuity mistake: When Amber and Ben are walking through the airport, and even when she hits him to flee, the group of people around them changes depending on the camera angle.
Continuity mistake: When Killian is talking to Agnes about the next kill, as she replies, "That's a tough one," her left index finger is on the corner of her mouth. After the camera cuts to Killian, the hand in several inches lower.
Continuity mistake: When Buzzsaw runs by Richards, cutting the pipe in half, he has the chainsaw on his left hand. The camera watches Buzzsaw turn around, and you don't see the chainsaw, as the rider's left hand is on the handlebar, controlling the turn. The camera cuts to Richards for a second, then back, and the saw is on Buzzsaw's hand again.
Answer: When Ben is walking to the apartment door, he has a huge case with him which is big enough to hold clothes and even shaving equipment. Ben entered the door code into the keypad which unlocked the door so the code was never changed.