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Empire Falls (2005) (TV) More at IMDbPro »

The Otto Meyer character's last name was changed from Meyer to Mayer to avoid possible litigation from someone of that same name while there were more than one Otto Mayers living in Maine.

As for the character of Buster one would assume that the name was changed for the same reason though when asked Empire Falls author Richard Russo stated on the set while filming was in progress that "I must have forgotten his name while writing the screenplay". The occupation of Buster/Brian was also changed from cook to busboy. The character's presence was greatly reduced in the movie as compared to the book as well.

The character wasn't completely eliminated however due to the need of Brian/Buster being let go to make room for the John Voss (Lou Taylor-Pucci) character thus setting up the climax of the movie.