Crew or equipment visible: Earpiece visible in Dane Cook's ear while singing the "Piggy-nose" song which then disappears.
Continuity: When Marie is making pancakes, she picks up the syrup to pour on Dan's pancakes with her left hand and starts to pour, then in the next shot she is pouring with her right hand.
Errors made by characters (possibly deliberate errors by the filmmakers): The cop takes Dan's driver's license after his accident and then later Dan says he can no longer drive because he doesn't have a license. Although the police can take your license in lieu of a cash bond, they can not take away your driving privileges. You can still drive while waiting for your court date by using the ticket as your driver's identification. Typically only your state's DMV or a judge can revoke your driving privileges.
Continuity: In the scene where Dan is talking to Cindy and Jim, the father and daughter that are going to syndicate his column, you can see Mitch's chair next to Dan move close so that Mitch's leg is touching Dan's and further away, then close, then far again to Dan's chair.
Audio/visual unsynchronized: When Dan drives his car, you can hear a diesel engine and when he starts it back up you hear a gas engine crank.
Factual errors: Dan's car, a Mercedes 300 turbo diesel, is shown filling up at an unleaded gas pump.
Continuity: During the end credits when everyone is dancing in a circle, Marie's strap on her dress is falling down on her arm, then it cuts to a different angle and the strap is magically back up on her shoulder.
Boom mic visible: At the dinner table, when the topic of forgiving pasts comes up, the boom mic falls into the shot. John Mahoney even breaks character to look up at it.
Continuity: When Dan is searching for a knife to cut the pie, the first time we see it, the pie is tall. When the camera cuts back to the pie, it is shorter.
Factual errors: Dan stops for gas in New Jersey while he and the girls are driving up to the family's house. He is shown pumping gas, but in New Jersey you are not allowed to pump your own gas. There are no self-service stations in New Jersey.
Errors in geography: At the end of the movie the family is seen driving back from New England to New York City. Their car travels west over the Queensboro Bridge from Queens into Manhattan. It makes very little sense to ever enter Queens when coming from New England if traveling into Manhattan. The Triboro Bridge (now called the RFK Bridge) which takes you from the Bronx to Queens can also take you to Manhattan. Entering Queens would make the trip longer and cause you to pay an extra toll.
Continuity: When Mitch and Dan and the rest of the family are sitting and talking with the reporters, Mitch and Dan's chairs go from touching to not touching to touching again,all throughout the scene.