Revealing mistake: Rocky, Apollo, Adrian, and Paulie are filmed from behind walking to Apollo's gym (notice Rocky and Apollo are the same height). When Rocky turns to walk in the door, you see heels at least three inches tall on his feet.
Factual error: After the match with Thunderlips the newspaper says it was Wednesday, May 15 1982, but that day was a Saturday.
oswal13Character mistake: During Mickey's MI it's stated that his blood pressure is 200/50 (that alone is ridiculous) and the doctor immediately says "OK. Let's start CPR." If Mickey has a BP he has a pulse, and any CPR certified healthcare provider would know that you can't do CPR on a patient with a pulse.
Revealing mistake: In a shot of Clubber Lang and his manager standing in the corner at the end of the first round during the rematch between Lang and Rocky, "Clubber" on Lang's boxing shorts and "Heavyweight Champ" on the manager's shirt are back to front, indicating that it is a reversed shot.
Continuity mistake: When Rocky is choking Thunderlips he does with his left arm, then after an angle change it's his right.
oswal13Continuity mistake: After the first match with Clubber, Mickey gets sick and Adrien makes a pillow with her coat for him. Just before he lies down his hat disappears.
oswal13
Answer: Clubber Lang worked his way up the professional ranks. If you notice, the challanger is still able to fight, the referee uses his own discresion to ignore the final punch as the match would have been called in Langs favour anyway