His answer when it came was sharp. Ruby knew that tone. It was the tone that said 'drop it'. And coming from him to her she found it unusual enough. But if he really didn't want to focus on the loss of his friendship with his charge then she would move on. Which she supposed was learning and growing as a person. She'd never have cared before. Of course it was highly unlikely she'd have been sitting on a park bench with an Angel a year ago either worrying about how likely Cas's words were to be true. It would make sense if Zach had done it, there was a beautiful cruelty to it.
"Making him forget..." she said, right then, so much the demon she was. "He'll have to learn again, about the blood, about Sam and me, about Lucifer being free. Its a hell of a tactic. Cruel but not just to Dean, it hits all of us, you, Sam. You angels really don't just sit on clouds wearing dipers with harps and arrows do you? Its what I would have believed when I was alive isn't it. Wrathful angels to make us Godfearing"
Not that Ruby knew anything about her past. She could have been that, she could have been a freaking nun for all she knew before she was a witch. She sort of doubted it though. That would have been silly. All she knew was if she'd had the resources and power to pull off what Zachariah had done to Dean she'd have done it. Before she'd been with Sam obviously. She'd never hurt Sam like that.
"What do they want Dean so bad for, Cas? Didn't he do his job and break the first seal? Wasn't that it for him?"