Continuity mistake: In the beginning of the movie, Sarah and Tom are at the airport returning from their honeymoon. While walking through the airport, Tom pushes Sarah and she gets coffee spilled on her shirt. Later, when she approaches Tom in the parking lot for a ride home, the coffee stain has suddenly disappeared from her shirt in this shot.
Revealing mistake: In the scene where Tom accidentally kills Sarah's dog, he is seen reading a magazine while struggling with the dog. The dog continues to gnaw at Tom's ankle, and eventually rips open his snap pants. In a couple of the shots, you can see an ankle brace that Ashton Kutcher wore to protect him from the dog's bites.
Continuity mistake: When Kyle is sleeping on the couch, in the wide shots from upstairs and downstairs the golf bag is behind his right shoulder. In the close-ups the golf clubs are behind his left shoulder. The sandwich, paper towel, mustard bottle, lamp behind couch also change in these shots.
Continuity mistake: As Tom drives out of the parking garage, 'Just Married!' is on the back window of his car. In the very next shot, pulling up to Sarah's parents' home, 'Just Married!' is seen again, but it is written differently than in the previous shot, most noticeably the heart over the letter 'i' disappears. Then when pulling away from the house, the 'Just Married!' is different yet again.