What is an example of verbal irony from the story "A Good Man is Hard to Find" by Flannery O'Connor?

This is an example of verbal irony because the grandmother is attempting to reason with the Misfit in an attempt to get them to let they go. She says:

"Listen," the grandmother almost screamed, "I know you're a good man. You don't look a bit like you have common blood. I know you must come from nice people!"

"Yes mam," he said, "finest people in the world." When he smiled he showed a row of strong white teeth. "God never made a finer woman than my mother and my daddy's heart was pure gold," he said.

The ironic thing, here, is that because he came from 'good people' doesn't mean that HE's good people.