Why does the grandmother call the Misfit a "good man" in "A Good Man is Hard to Find" by Flannery O'Connor?

One of the most baffling moments in Flannery O'Conner's "A Good Man is Hard to Find" occurs near the end, when the grandmother insists the Misfit is a "good man" despite repeated examples to the contrary. It's never explicitly stated why the grandmother persists in doing so, but we can make at least two assumptions regarding her motivations based on the context. First, it seems like the grandmother is trying to flatter the Misfit by calling him a good man and, in doing so, convince him to stop murdering her family members.  Second, by calling the Misfit a "good man," the grandmother could also be trying to convince herself of this fact. Panicking in a dreadful situation, the grandmother appears to be grasping at any kind of security available to her, even if that means clinging to an increasingly absurd fantasy that the Misfit is a "good man." Therefore, with these two ideas in mind, the grandmother's interactions with the Misfit become more and more desperate.