Uncle Billy is the one true evil character in "The Outcasts of Poker Flat"--a cowardly man who is guilty of the original charges against him and who seals the others' fate when he takes off with their food and mules in the middle of the night. While the others have been run out of town for plying their trades--prostitution by the women, and Oakhurst's gambling--Billy is a "drunkard" and "sluice robber." The women have earned their money in an honest though immoral manner, while Oakhurst is run out of town simply because he has won money from the other townspeople, who are
... experiencing a spasm of virtuous reaction, quite as lawless and ungovernable as any of the acts that had provoked it.
While the others work together to try and ease the problems they face, Billy simply runs away with the provisions, living up to his reputation as a thief and leaving the others to die alone in the wilderness.