Factual error: In one scene Cobb and the sportswriter doing his biography are driving across the country to get to the baseball Hall of Fame. They are stopped next to some railroad tracks fixing a flat tire, and a train goes by that has Burlington Northern markings (BN). Burlington Northern didn't come into existance until ten years or so after Mr. Cobb died.
Character mistake: When Frank says to "V" that his mother died before he was born, "V" replies that she doesn't think that's possible. She is wrong. Although it may be uncommon, some babies ARE successfully born even after the death of its mother (usually with an emergency procedure).
Visible crew/equipment: During the performance of "Gotta Get A Gift", there is a handheld camera shot where the turtles are walking towards the camera singing the chorus while the camera moves around them. Just before the camera cuts to another shot, a stage light can be seen in the background to the left of shot, behind Michelangelo. Additionally, two shots after this, the same stage light can be seen again in the far background and can also be seen right at the start of the shot after that for a brief moment.
Revealing mistake: Most of the police cars are late model Ford Sierras, but any police car that crashes has been substituted for a much older early model Sierra.
Continuity mistake: Mr Sullivan gives the stolen snow blower to his ex wife's husband for safe keeping, suggesting a tarp in the back of the garage. In a subsequent scene the snow blower is back in Sully's pickup for all to see.