The grandmother is typically regarded as an unsympathetic character, and readers are generally inclined to be suspicious of anything she says. So when she calls Red Sammy Butts a good man, readers can infer that her fulsome endorsement may not be entirely accurate. The jolly filling station owner with the happy smile may seem like a perfectly pleasant person, but the grandmother's judgment is wrong in enough other cases that readers must wonder if she's correct in her estimation of his character.

Certainly, the grandmother's endorsement of Red Sammy seems entirely self-serving. One could argue that she only calls him a good man because he's about the only person who appears to enjoy engaging in conversation with her. In the selfish grandmother's mind, being a good person is equated with doing something nice for her.

In any case, it does seem that Red Sammy's conversation with the grandmother is at least in some ways a part of an elaborate sales pitch. Red Sammy's face is already plastered all over billboards, so readers know he's pretty good at self-promotion. One gets the impression, then, that his nodding along with the grandmother as she spouts her half-baked opinions and prejudice is more to do with customer service and selling products than it is about being a genuinely good man.