Visible crew/equipment: In the scene after the huge fight with the Buddists, Jack Nicholson speeds off in his Land Rover and cuts into traffic to get away from the monastary. If you look three cars back there is a state trooper weeving through both lanes to make sure the set is closed. He stays visable throughout the scene.
Factual error: When Dave is at the Yankee game and he is telling Linda he wants to marry her from the field, it is impossible for his voice to ring throughout the whole stadium without a microphone (even though it echoes as if he were using one.). Similarly, he wouldn't have been able to hear Linda when she shouts "I'm over here."
Revealing mistake: When Jack and Adam are in bed together, after Jack's "flatulent" moment, Adam tries to keep from laughing while answering Jack's question. The blanket covering Adam's face is obviously covering up an hysterical set moment.
Continuity mistake: When Jack speeds out into the road in the Land Rover, there are several cars in the background. However, in the next immediate shot, when we look out the back window, there are completely different cars behind them.
Continuity mistake: After the fury fighters' meeting with John McEnroe Dave asks Buddy to talk to him in private. The go into the multi-purpose hall of the community center which has a stage on one side. In all wide shots and one close-up we see them talking in front of the stage, in all other close-ups in front of an inscription on the wall which is about 20 meters away.
Continuity mistake: In the beginning of the film, it shows Dave as a child and according to the film it is Brooklyn 1978. Dave is wearing a Dukes of Hazzard t-shirt, but that show didn't debut untill 1979.
Factual error: After the Yankee game when Adam Sandler and Marisa Tomei are going home via the subway, they show Yankee Stadium in the background and they are standing on the platform further away from the stadium. If they live in Brooklyn, they should be on the platform closer to the stadium as that is the one that is south bound towards Manhattan and Brooklyn. The one they are on goes north. Why would they be going north away from home at that hour?
Continuity mistake: When Buddy and Dave are on the bridge singing, when Buddy has the papers they are held together with a paper clip. In one shot when Dave has the papers, they are held with a staple.
Continuity mistake: After their encounter with the monks, Buddy and Dave speed off and come out onto a road. The first shot sees the whole car come onto the road, where there is a double unbroken line in the middle of it. The shot changes to Buddy and Dave in the car. Watch through the back windshield. The double unbroken line has turned into a single, broken line.
Continuity mistake: When Dave lets his lawyer hear what went on in the car, things that were said have been shortened and shuffled around.
Continuity mistake: When David is at his first anger management meeting, Lou is wearing a black shirt that sometimes covers his stomach and sometimes does not, riding up and down depending on the shot.
Continuity mistake: When Adam Sandler is outside on the phone with his lawyer and the NYC is in the background, the boat wake disappears and reappears in the shadow of the bridge.
Continuity mistake: As Adam Sandler goes down the courthouse steps after his third trip to court, the same red headed woman passes him twice.
Factual error: When Dave and Buddy get to Boston, Dave is using his cell phone, mentioning that they didn't have to take a five-hour trip to Boston just to find out that Buddy's mom was getting a Jelly Bean removed from her nose. Problem is, he's calling from the ramp staircase of Alfred Lerner Hall at Columbia University, which is in New York City, not Boston.
Continuity mistake: At the beginning of the movie when Adam Sandler is about to get on the plane they do a couple of close ups of his face. Whenever they cut to something else and then come back to his face his sideburns are shorter. This happens a couple of times in this scene.
Continuity mistake: When Dave first meets his 'group', just after Stacy and Gina kiss, one of the group members is shown wearing an Iverson headband. A few seconds later as the camera pans back to him, the headband is backwards.
Revealing mistake: When David's car does the little jump while driving to the Yankee's game, you can see that it is a stunt driver driving, not Adam Sandler. This is most obvious when the light hits his face for a second.
Continuity mistake: After his first court case Dave goes to the Community Center where Buddy does anger treatment. When he picks up one of Buddy's books from a table there are some wooden chairs scattered in the background. In the next shot we see him from an upstairs landing, and there is now one wooden chair with its back directly at the table, and one white plastic chair where the wooden chairs were before.
Factual error: When Dave is on the plane the flight attendant is talking about "how their country is going through a very difficult time right now" meaning the 9/11 attacks but later on in the movie when Buddy is in the shower and Dave is talking to his lawyer on the phone on the roof in the background you can see the twin towers.