I think it would be missing Tim's point to suppose that he's ascribing some sort of quasi-Kantian value-in-itself to Aztec meta-ethics, when all he seems to be noting is that the Aztecs got torture wrong. If you want to reserve 'virtue' for a more specific idea and historically bound idea in Western ethics, I doubt he'd mind your paraphrasing his point in your preferred idiom. It takes a pretty wild imagination to read Tim's comment and think he's saying that the Aztecs considered human sacrifice a summum bonum or unconditionally and in-all-contexts good. That's just not what the conversation is about.