What was Herman calloways reaction to buds claim that he was his son in Bud Not Buddy?

In "Bud, Not Buddy," Herman Calloway initially reacts with disbelief and anger to Bud's claim that he is his son. He is dismissive and skeptical, questioning Bud's story and expressing frustration. However, as the story progresses, Herman's attitude shifts, and he begins to show a more compassionate side, ultimately leading to a deeper understanding of Bud's situation and a connection between them.