How do I Describe Sam's feelings about Red Chief by the end of the story? How does he change from the beginning of the story?

In O Henry's "The Ransom Of Red Chief", Sam is the "brains" (if there are any brains) of the operation.  At the beginning of the story, he reasons that given the size of a child that a child would have to do what he says.  He also wrongly assumes that "Red Chief" will be afraid of them and that the parents will gladly pay a ransom to get him back.

He is wrong.

At the end of the story, he discovers that the boy is both cunning and conniving- a trait that given his parents, the Dorsetts, stunning counter demand, he has obviously inherited. Nothing he assumed about the boy was correct.