Visible crew/equipment: After the little girl leaves the grocery store with Dodger, the monkey, the overhead microphone can be seen above her head.
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: When the doctor is cutting the forehead, a red tube to release fake blood can be seen behind the scalpel. (00:30:12)