Revealing mistake: A policeman fires during the robbery even though the slide on his automatic is visibly locked back and open.
Other mistake: At the beginning of the third chapter ("El Chivo y Maru"), when the Comandante and Gustavo are driving to see Chivo, the Comandante says to Gustavo, "Make a right here."; however, Gustavo ignores him and never makes a right. He just keeps going straight.
Continuity mistake: Chivo's sandwich keeps changing shape when the cop visits him.