What reason is given for Russell's heroism in the conclusion of the novel, Hombre?

In the novel's conclusion, Hombre's death is considered an act of heroism, since he did "what he felt had to be done. Even if it meant dying." Firm and unchanging in his beliefs, he nevertheless "let people do or think what they wanted." According to the narrator, Russell was a significant moral force, although he "never changed the whole time . . .