"When Doodle was five years old, I was embarrassed at having a brother of that age who couldn't walk, so I set out to teach him." ... "Don't hurt me, Brother," he warned. "Shut up. I'm not going to hurt you. I'm going to teach you to walk." I heaved him up again, and again he collapsed."
Man vs Self
"As I waited, I peered through the downpour, but no one came. Finally I went back and found him huddled beneath a red nightshade bush beside the road."
Man vs Nature
"Limply, he fell backwards onto the earth. He had been bleeding from the mouth, and his neck and the front of his shirt were stained a brilliant red. "Doodle! Doodle!" I cried, shaking him, but there was no answer but the ropy rain."
In this part of the story we read about Doodle's brother being embarrassed of Doodle and trying to make his brother "normal" by teaching him how to walk, but he gets frustrated when Doodle keeps falling. We can infer that Doodle feels unwanted by the way his family acts towards him.
In this sentence that we read from the text we can infer that Doodle's brother feels bad about leaving his brother behind and his first thought is to go back and check on him. He has a moment to think for himself and he realizes that there is no reason to be this upset and he should learn to control his emotions towards his brother.
In this scene we read about Doodle's death and the big impact it has on his brother. Doodle had an illness that his family believed would give him a short life to live and in the story when we read about Doodle trying to keep up with his brother we can infer that Doodle over worked himself which caused his body to give up.