Character mistake: When Stan inflates himself, Michael asks, "How'd he do that?", implying that he doesn't know the rules of the Looney Tunes world. Since Michael was rolled into a ball by the aliens earlier in the film, this shouldn't be too much of a surprise.
Suggested correction: When Michael was rolled into a ball, he wasn't concerned with how that was possible and soon after he forgot about it. He was more concerned with dealing with the Monstars at the time and, in particular, helping his cartoon friends preparing for the game. When Michael witnessed Stan being flattened and inflated, it looked particularly strange and unfamiliar to him, unlike before as he couldn't watch himself experiencing being rolled into a ball. And that is what triggered his response about questioning how it was possible.
Character mistake: When Nanny is coming home from getting the collars, she calls for Roger and Anita to come downstairs. Plowright accidentally says "Roderick, " rather than "Roger."
Character mistake: At the Gazette office, as Ms. Rees-Jones watches, Steven scrolls up the next front page of the Gazette on his PC and under the photo of Chuck Hughes it reads, "...dead at age 37." However, when Frank gets into his car after being kicked out of the cemetery, under the current Gazette headline it reads, "30 yr. old Chuck Hughes who died of a mysterious heart ailment..." (00:03:10 - 00:05:30)
Character mistake: While the engine room is flooding, Stepanik tries to put a jubilee patch on the pipe by walking towards and deflecting the water. While it looks cool for the movie, it is definitely not the correct way to apply this type of patch.
Character mistake: At the boat when the two bodyguards frisk Shag, he fakes a gay yelp and then walks away with Erin. You can see the one guard on the right, try not to break (crack up) as they walk away.
Character mistake: At Governor Tracy's acceptance speech, she thanks her husband, Dennis, and two children, Andrew and Patrick. However, she has a son and daughter, not two sons. Additionally, her husband is credited as "Donald" not Dennis, who was played by Patrick Pankhurst.
Character mistake: Stephen Baldwin is alternately referred to as Mark and Luke Dodge, without explanation as to which is his real name.
Character mistake: When Harry takes the kids to his business, he's showing them how he "restores" cars. After putting the bumper on, Harry says, "Transmission. The sawdust quietens the gears and let's the engine run as sweet as a nut." Putting sawdust into the transmission would not change how the engine runs as they are two separate components. It may make the transmission quieter but would have zero effect on the engine.
Character mistake: When Greg and Rose are playing backgammon, Rose counts the middle of the board as a place to count when moving a piece, but the middle of the board isn't a place to count.
Character mistake: When discussing the potential fallout of ousting the new president, Douglas says that because there's no vice president that according to the 25th Amendment the Speaker of the House is next in line. Not true. The Amendment itself is silent on the order of succession after the Vice President. The Constitution leaves the order of succession after that up to Congress, and the Speaker of the House is listed according to the Succession Act of 1947, not the 25th Amendment.
Character mistake: Reverend Sultan stated James Roper lost to Terry Conklin 10 years ago. Later at the press conference Roper stated he was 17 at the time. During promotional videos for the fight, the "tale of the tape" listed Roper as being 30 years old, not 27. (00:21:29 - 00:33:37)