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).
At the end of the film, Charlene is in the new office with Howie and closes the blind. In the next shot, a long shot from a helicopter, the blind is clearly open.
On the night of her party that goes wrong, Sarah's hair changes three times in a short amount of time.
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.
After Peter tries to lock Charlene outside of the house when he first meets her, he tackles her and then throws her in the bushes. After telling the nosy neighbor that everything is fine, Peter starts walking her back inside. From the shot outside the house, Peter has nothing in his hands. But when they step inside, he magically has one of her shoes in his hand and he sets it on the table.
When Peter prepares to open the door to meet Charlene for the first time he first dims the lights but actually there is only a switch and no dimmer.
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.
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.
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.
The cable to the squib is seen running down from Charlene's foot as she falls backward on the couch in slow motion.
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.