Continuity mistake: When he's called in to see the Captain, Montag wears his wristwatch turned inward (with the face resting over his pulse point). Seconds later, though he hasn't touched it, the watch has rotated itself 180 degrees and is now on top of his wrist. (00:26:05)
Fahrenheit 451 (1966)
1 continuity mistake
Directed by: François Truffaut
Starring: Julie Christie, Cyril Cusack, Anton Diffring, Oskar Werner
Deliberate mistake: Montag's hair gets intermittently shorter, longer and shorter again (and acquires a "cow lick" that wasn't there before) near the end of the film. (Oskar Werner had clashed with Francois Truffaut and deliberately had his hair cut to spite director.)
Guy Montag: Tell me, this uncle of yours, did he ever tell you not to talk to strangers?
Clarisse: No, he did say once if anyone asked how old I was to say I was 20 and light in the head. They always seem to go together.
Guy Montag: Light in the head?
Clarisse: Mm-hmm, loopy, crazy.
Trivia: In keeping with the theme of no books this movie has no text visible anywhere except the opening theatrical logo. Even the credits are not shown on the screen. The only symbols shown in the movie are numbers, such as the 451 medallions on the fire crews and their equipment. Signs can occasionally be seen in the background.