Why does Palmer begin to question his real reasons for sending Nipper away? What does he come to understand?

Palmer experiences tremendous relief when Nipper leaves. He realizes how tense and worries he has been for many months trying to keep Nipper a secret from his family and safely away from Beans and Mutto. For this reason, he begins to see that letting Nipper go was for him as well as Nipper. He also realizes that he has endured great losses through all of this: he has left the gang, thinks of himself as a traitor now, and has lost his friendship with Nipper.