Continuity: When Peter takes Mrs. Arness, her dog William, and golf caddy out for a game of golf, there seems to be an extra player in their foursome. In the golf cart, sitting just behind the four, is a woman wearing a hat, taking off her socks. The woman is dressed exactly like Mrs. Arness. The woman then disappears entirely after Mrs. Arness takes a swing (she is Mrs. Arness' stunt double).
Continuity: On the night of her party that goes wrong, Sarah's hair changes three times in a short amount of time.
Factual errors: When Charlene uses the speed dial on Peter's cell phone, you can hear the tones as a number is being dialed. You can't hear the tones for the numbers if you do that in real life.
Revealing mistakes: In the beginning of the movie, when Peter gets the instant message at work and Howie goes to look at the laptop, the Apple logo is not lit up as it would be when the laptop's power is on.
Continuity: When Charlene is talking to Widow for the first time beside the pool, the water of the pool is very active. When Charlene comes inside after the chat, the water is perfectly still.
Continuity: The shoulder space between Peter and Howie when Peter introduces Howie to Mrs. Arness at the country club.
Continuity: When Charlene is trying to teach Peter how to talk dirty, his shirt is tucked in. In the next shot, one side is untucked.
Continuity: When Peter is trying on clothes for his date, he fluffs the color of the blue shirt before he puts on the sweater. In the next shot, one side of the collar is in and the other is out.
Crew or equipment visible: The cable to the squib is seen running down from Charlene's foot as she falls backward on the couch in slow motion.
Audio/visual unsynchronized: When George is telling his mother how cool his father has become, the camera is directly on the boy but his lips do not move.
Revealing mistakes: Near the end when the car pulls up to the house, there is a line of parking meters with a fire hydrant sitting right in between two of them with no extra space.
Crew or equipment visible: When Peter is preparing to meet Charlene for the first time, he opens the glass refrigerator door and the reflections of the cameraman and another man can be seen.
Plot holes: After Peter gets caught with Charlene it goes to him in his boss' office being told off about what happened. It seems like it's the next day, but then it shows Peter and Charlene talking after Charlene just met Widow, and Peter gets a call off Sarah who's still in the party. Plus Peter is now stone cold sober and when he got home he was extremely drunk.