Dressed to Kill (1980)

Deliberate mistake: Has there ever been a more obvious body double than the one used for Angie Dickinson in the shower scene? Not only does the top of every shot stop right at the collarbones, she is much taller than Dickinson, she has a much deeper tan and (of course) her breasts are much, much bigger. In fact that is Victoria Johnson, Penthouse Pet of the Month for August, 1976.

Plot hole: After his mother's death, Peter sets a camera up outside her therapist's office, so he can see who goes in and who comes out; he thinks his mother's killer might be one of the doctor's patients - a tall woman with long blonde hair. All he sees is people going in and people coming out, and then he sees her - the tall blonde. Problem: He never saw her going in, only going out, which is critical, because the killer is the therapist - a tall man - wearing a long blonde wig and make-up. Of course no-one says anything about "We never saw her going in, only out, so it must be the therapist!"

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Continuity mistake: The amount of blood on Kate's face decreases between the time she is attacked and discovered. The pattern changes from shot to shot as well. (00:34:15)

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Liz Blake: Thank god, straight fucks are still in style.

Kate Miller: Maybe there's something wrong with me.
Doctor Robert Elliott: There's nothing wrong with you.
Kate Miller: Do you find me attractive?
Doctor Robert Elliott: Of course.
Kate Miller: Would you want to sleep with me?
Doctor Robert Elliott: Yes.
Kate Miller: Then why don't you?
Doctor Robert Elliott: Because I love my wife, and sleeping with you isn't worth jeopardizing my marriage. Is it worth it to you?
Kate Miller: I don't know.

Doctor Robert Elliott: Doctor, I am not paranoid. Bobbi was making threats over the phone. She said she's going to hurt me. My patient was slashed to death. And now my razor is gone. Now you don't have to be a detective to figure it out, do you?