What is a way at the end of the story that the theme breaking expectations is conveyed?

There isn't a flashback that I recall at the end of the story. I think the narrator finally realizes that something is wrong. They try to race the storm home, but eventually Doodle collapses again. Like he did in an earlier part of the story, Doodle calls out for the narrator not to leave him. The narrator, however, is feeling cruel, since his pride is shattered and they had failed. He runs away, leaving Doodle far behind. He runs for a while and then gets tired, and realizes that what he did was wrong. He waits up for Doodle for a while, but when he does not show, he goes back and finds him in the same spot, lying on the ground, his face buried in his arms. Doodle is dead because he could no longer live up the the narrator's expectations.