Why did they change Cartier's age?

I looked him up and imdb has him listed as born on March 22, 1922 which makes him turn 28 a few weeks before his April 17th 1950 bout with Bobby James. But even weirder is that boxing encyclopedia has his birthday listed as March 29, 1924. Either way he is either 26 or 28 during his one and only fight against Bobby James yet the movie says he and his twin are 24. Is this to make it seem more reasonable that he is a budding contender and still has a shot at a title bout. Of course despite a solid career (46-13-2) he never does quite get a title bout. Just curious if anyone knows why this occurred.