When Paul is reading the newspaper article about the Bishop case being dropped,the game schedule to the left of the paper shows dates March 11th and March 12th. The NFL regular season is played from September to late December.
When Paul confronts his brother in the bathroom he locks the door behind him then when he leaves he doesn't unlock the door.
The climactic showdown, the last game of the regular season, takes place on a Monday night. For better or worse for NFL fans, the final Monday Night Football game is always the next to last weekend of the season, never the final game of the regular season. Rationale: If a team plays on a Monday night, then qualifies for the playoffs the following weekend, it would be at a disadvantage due to a day less of preparation time.
When Paul's friend shows Paul the Giant's upcoming schedule, it only shows a 14 game season (should be 16).
When Paul and Sal are discussing the Giant's schedule next season, it is mentioned that they will be playing both New England and San Diego. Since the New York Giants are in the NFC, there is no way that they would play both New England and San Diego as both are in different divisions. Within the AFC and NFC teams only play teams from one specific AFC division each season.
"QB" in the newspaper articles refers to "Quantrell Bishop", not the slang term for "quarterback", therefore the fact that his character is a linebacker is not a goof.
When Paul is reading the newspaper about the Giants' actions regarding the suspended player, two short paragraphs are repeated several times to give the appearance of more news copy.
When Paul is sitting in his booth reading the newspaper, the article says that it is not known if Quantrell Bishop "will travel with the team Saturday when it heads to Carolina for the key showdown, which has strong playoff implications."
At the same time Paul is reading the paper, he is also listening to sports talk radio. The announcer states that breaking news has been received that "... Quantrell Bishop will not be eligible to play in this Sunday's key showdown in Dallas...".
When Detective Velarde flashes his badge in Paul's hospital room, it is not a New York City detective's badge.
When Paul and his mother argue in the car, on the way back from his brother's home, about him masturbating, Paul denies it. His mother's response is supposed to be, "You think I don't see those tissues, Paul?" but she messes up the line, instead saying, "You think I don't see those tissue, Pauls?"
The bar "Sharky's" seen towards the end of the film where Paul Aufiero encounters Philadelphia Phil is actually located in the northern section of Staten Island, and not Philadelphia where the scene was supposed to have taken place.
The movie shows Paul entering Pennsylvania on the Pennsylvania Turnpike. When he stops to change at a rest area, it is obviously in New Jersey, due to the fact one can see a map of New Jersey on the wall of a payphone as Paul is walking to the restroom to change.
When driving to Giant Stadium from Staten Island, the montage shows signs of the NJ Turnpike South. East Rutherford is north of Staten Island.