While he's right, Carol can't manage to agree. She's not sure what she did, horrible and repugnant she agrees, was fucking up. It didn't make much difference in the end but she's seen what can happen from inaction, from waiting. Rick was busy farming and the council was busy hand-wringing -- she blames none of them for it. That's what good people do when faced with impossible choices.

That's why Tyrese stayed back with Judith while Carol did what was necessary. Carol isn't sure whether she can still call herself a good person, but she was willing to give that up for the sake of people she cares endlessly for.

"That doesn't mean they can come back from it." Right reasons or wrong ones, what's done is done, and she has to take every breath of the rest of her life feeling it.