Revealing mistake: Some shots used in the scene where Johnny runs from the Nova helicopter were shot using the small toy version of Johnny. There were no mountains in the area and a small version was filmed heading towards some big rocks with the camera on the ground to give the impression they were in a mountainous area. (01:30:15)Padzter
Visible crew/equipment: When Number 5 plays with the light switches on the way to the disarming section, a coffee serving robot comes through the corridor, and the reflection of the camera is visible in the coffee pot. (00:12:15)
Continuity mistake: Just before we see Johnny fall off the bridge we see a shot of him speeding past some roadblocks. Look at the size of Johnny compared to the roadblocks. They are practically bigger then him. This was obviously a small replica robot filmed with the camera on the ground, to give off the impression it was the real thing. (00:20:45)Padzter
Continuity mistake: During Frank's second visit to Stephanie's home the stack of pancakes J5 is holding decreases from a load to a few over several shots.
Continuity mistake: At the beginning of the movie when the "Red Army" approaches, the tank has his barrel locked in a transportation brace. As soon as the tank fires back, the brace is gone.
Continuity mistake: In the scene right after Number 5 almost drives the snack wagon into the lake and the Nova guys are shooting him, you clearly see him get shot in the hydraulic pistons which control his head motions. Yet, in the next scene (in the truck) Number 5 comfortably moves his head.