Corrected entry: According to the 'movie timeline', we know Mickey passes away in August 1981. Shortly after Mickey's death, when Clubber is being interviewed about his upcoming re-match with Rocky, one of the sportscasters makes mention that Rocky's attempt at a comeback at "34" are pretty long indeed. However, during the rematch fight in Rocky II with Apollo (movie timeline has that fight in November 1976), one of the commentators says Rocky is "31 years of age". That fact would put Rocky's birth year sometime in 1945. Rocky could not have been 34 right after Mickey's death in late 1981. He would have been at least 35, if not 36.
Corrected entry: When Rocky is trying to catch up with Apollo during their jog, he has flashbacks of his first fight with Apollo and Mickey yelling at him. In the flashback, the punches he "remembers taking" from Clubber, and especially the fashion in which he was knocked down, do not match at all the happenings and his knockdown from the first match. Also, the knockdown scene Rocky envisions shows him being hit by a black glove, Clubber wore red gloves in the first fight.
Corrected entry: When Rocky is going to fight Clubber for the first time and both fighters are preparing to go into the arena, an argument breaks out on the stairwell. Clubber needs to be restrained and is yelling at Rocky. At one point, instead of calling him "Balboa" he calls him "Stallone" (the actor who played him Slyvester Stallone).