The symbolism of Bonaparte's name says a great deal about his developmental changes. Like the Bonaparte of O'Connor's story, the real Napolean Bonaparte was the cause of hundreds of senseless deaths and viewed by many as a traitor.
This like-named character did not begin as a charlatan. In Section I of O'Connor's story, Bonaparte views himself as a congenial man; one who considers his prisoners as friends rather than enemies. He even says, "after the first day or two we gave up all pretence of keeping a close eye on them," an indication that a mutual trust and respect had been cultivated. Bonaparte talks about playing cards with Belcher and Hawkins. He calls the prisoners "chums" and genuinely seems to enjoy the time they spend together.
However, by Section IV, Bonaparte cannot stand up for his own values. As the two prisoners/friends are led to their executions, not only does he do nothing to stop it, he even pulls the trigger on Hawkins, the first prisoner to die (after Donovan's bullet fails to kill the man).
Bonaparte has betrayed himself as much as the prisoners. Their pain and humiliation is over as they crumple to the ground. His is just beginning, for he will have to live with his betrayal for the rest of his life. No longer does he view the conflict as essentially political maneuvering; the consequences are too real.
He saw things from Donavan's point of view, he did realize the harsh truth that they are hostages not friends.