In Will Smith’s new movie, “Concussion,” the former N.F.L. player Dave Duerson confronts the film’s protagonist, the pathologist Bennet Omalu, whose findings of chronic traumatic encephalopathy in pro football players shook the league. Duerson blocks the Nigerian-born Omalu from entering a medical conference, calls him a quack, and tells him to go back to Africa and to “get away from our game.”
Omalu, played by Smith, retreats in shock.
According to the Duerson family, that confrontation, and at least one other scene in the film that portrays Duerson as disreputable, did not happen.