Who is Aeromexico Pilot's Brother from Legends of the Fall and what is their importance?

In the short-story, Revenge, the Aeromexico pilot's brother is an official in the Mexico City government. His pinstriped suit and demeanor mark him as a fine politician, but he doesn't want to involve himself in Cochran's revenge because he has a family to protect. He helps Cochran because he loves his brother and his brother cares for Cochran.