What did Elie mean when he prayed for strength to never do what the Rabbi’s son had done?

Rabbi Eliahou is a good man, admired by all, and he and his son had remained together for three years in the concentration camps. Eliezer tells the Rabbi that he hasn't seen the man's son, but after he leaves, he realizes that he actually had. The son had seen his father falling behind in the pack, but he had continued to run farther and farther away from him. He had been trying to get away from the burden of looking after a weak father. Eliezer prays to God for the strength never to act in the same way that Rabbi Eliahou's son did.