Continuity mistake: Right at the end, the insurance man gives Charlotte Jewel Mayhew's letter and in the next shot of him, his hands are empty. But in the following shot he's holding the letter again.
Audio problem: After disposing of Dr. Drew's supposedly dead body, Miriam tells Charlotte to get out of the car and go up to her room. Charlotte has been wearing thin slippers on her feet yet when she steps onto the porch, you can hear the sound of heels as she walks. (01:57:25)
Continuity mistake: When Charlotte shoots Drew, her hair is in plaits that are on top of her head, but as time progresses so does her hair. When they are disposing of the body, her hair is down; and when she enters the house, it is completely down and brushed out.
Factual error: Charlotte tells the sheriff that when her cousin Miriam arrives, she will know how to handle the County Commissioner. Louisiana doesn't have counties. They have parishes. (00:25:25)
Revealing mistake: When Miriam pushes Velma around in the hall, Velma collides with a wobbly banister - one that won't hurt Agnes Moorehead, the actress playing Velma.
Factual error: The party scene at the start of the movie is set in 1927, but all of the women have mid-1960's hairstyles.
Continuity mistake: Near the end, Velma wants to take Charlotte away from Miriam and Drew; Velma handles the needle and syringe on the bedside table and puts them at the back, but when Miriam comes back the needle and syringe are back in their original spot.
Audio problem: As Miriam is about to hit Velma with the chair at the top of the stairs, you can hear Velma scream before she actually does; the sound and action aren't synced properly.
Character mistake: When the sheriff confronts Charlotte after she has shot at the bulldozer operator, he tells her that her gun is unlicensed, but he will overlook it. Louisiana does not have, and never has had, any form of gun licensing or registration.
Plot hole: The local newspaperman points out Miriam to the insurance man before she gets out of the car, and the car is across the street - there's no way he could know it was her before she got out of the car.
Suggested correction: Of course he could have known her car, and since her husband was dead, who else would be in it?
Miriam didn't have a husband and Charlotte says in the film that she rented the car for Miriam.
Plot hole: In the beginning, Charlotte insists to Velma that cousin Miriam is coming, but Velma says "She's never answered any of your letters." And Drew says she's not coming. But when Miriam does come, only seconds later, Velma and Drew now act like they were expecting her. Velma says "You nearly beat your telegram. We weren't expecting you till tomorrow." It's like the film has been badly edited, with Miriam's announcement of her arrival ending up on the cutting room floor.
