Revealing mistake: When Samantha kills Mrs. Parker by crushing her head with the basketball, the dummy replacing the woman is visible.
Revealing mistake: When the bully's held up by Sam wires can be faintly seen.
Deadly Friend (1986)
2 revealing mistakes - chronological order
Directed by: Wes Craven
Starring: Kristy Swanson, Anne Twomey, Matthew Labyorteaux, Michael Sharrett
Plot hole: It seems unlikely Paul could've just taken Sam's body out of the hospital with ease and not run into security.
Upvote valid corrections to help move entries into the corrections section.
Suggested correction: Saying that something "seems unlikely" isn't really good enough to constitute a plot hole.
Tom: Hey, she's dead? Hey, what the hell are you doing, you didn't say anything about a dead body, we were supposed to save her life.
Trivia: Kristy Swanson received coaching from a professional mime in order to properly move like a cyborg.