Continuity mistake: When the thugs crash against the cardboard boxes, the stuntman flies face down horizontally, yet a frame later he is flying upwards, as if ejected.
Continuity mistake: The chopper lights a bright laser light that reflects on Jack's forehead. When the crane behind appears, the light disappears, yet in the immediate close-up of Jack's face the beam reflection is still there.
Continuity mistake: Jack shoots at the elevator glass ceiling, but a frame later the remaining pieces have changed.
Continuity mistake: When Benedict pulls the corpse's finger, his watch is right next to the suit's sleeve. A frame later there's a 5 centimeter gap in between both.
Continuity mistake: Arnie tells Jack Slater, "Call my office," then there's a side angle of Arnie, and it is very obvious that it's not him but a stunt double.
Continuity mistake: During the shootout the baddie lying dead on the couch has his head turned to the left. A frame later it's facing the right side.
Revealing mistake: When Arnie is talking to himself as actor Jack Slater, right when he says "You're the best look-alike I've seen" his eyes are looking slightly sideways, away from Jack, and not where they should. Obviously Arnie was talking to an empty place but missed.
Continuity mistake: In the alleyway, the thugs' truck crashes against the boxes sideways, from a 7 O'clock position; yet a frame later it is crashing from a 9 O'clock position.
Continuity mistake: When Danny enters the theater for the preview, the wetness of his hair changes back and forth.
Continuity mistake: When Danny's mom is asking him why he missed school, the purse's strap on the table behind changes positions between shots.
Continuity mistake: When Danny suddenly appears inside Arnie's car, between the chase and explosions until they park the car, none of Danny's movements and positions match between the close-ups and the wide angles.
Visible crew/equipment: At the end when the projector starts by itself and lights are going crazy, in one of the windows of the projection room, a hand holding a light (making it move) can be seen. Look at the farthest left window.
Chosen answer: The kid points them out in the film, in order to convince Arnold's character that he inhabits movieland. Also, after Arnold's character falls into the tar pit he is able to completely wipe himself clean, an obvious intentional continuity error.