Deliberate mistake: When the scanners escape the apartment in the van and the assassins are in pursuit there is a street view shot of the assassins driving up next to the scanners' van. If you watch the street on the right side of the screen you can see people stood watching the filming in groups, out of harms way. (00:50:28)
Scanners (1981)
1 deliberate mistake
Directed by: David Cronenberg
Starring: Patrick McGoohan, Jennifer O'Neill, Lawrence Dane, Stephen Lack
Continuity mistake: After the scanner's head explodes, not only is the table clean in the next shot (as already submitted) but Revok himself is as clean as a whistle. He was sat right next to him. (00:12:33)
Paul Ruth: I want you to access the Ripe program. I do not have ConSec computer clearance.
Cameron Vale: Neither do I.
Paul Ruth: But you do have a nervous system. And so does a computer. And you can scan a computer, as you would another human being.
Trivia: Scanners is identified as having the first known media depiction of psychic activity directly or indirectly causing nosebleed. This concept has since become widespread in movies, television, and comic books/graphic novels.