The "precipitous path" continues the early metaphor of the mine decoying Charles Gould "further than he meant to go." Allegorically, Charles is doing much more than arranging payment for soldiers: he is signing the moral meaning of the silver mine over to Father Corbelan and Hernandez. His full understanding is accompanied by a look that compares the flattened Don Jose with the "erect" Antonia: I don't think it's a stretch to say that he understands himself and Don Jose as equal victims, two crusaders for a moral society who have been "vanquished," not by "monstrous crimes" alone, but also by "monstrous illusions," i.e., ideals, as embodied by the patently unvanquished Antonia.