She stared at him for a moment. John was a sore spot for her ever since learning he'd killed her father - she still wasn't even sure if Sam remembered telling her, or if Dean knew. But she could put that aside, for now, for her friend.
"How could he have known? Your dad never should have asked that of you." Jo shook her head over the unfairness of it all - first Sam, now John? It wasn't fair of either of them to put this all on Dean. "If he had known, he should have told you so that it all could have been avoided. It's not your fault, Dean."