We [or at least, I am not] aren't talking about Mab's morality, we are talking about Harry's. As an outside viewer, I judge Harry's actions on the basis of \my\ morality. Consequently, I find many of his actions to be morally questionable.
There are quite a few different versions of morals where one doesn't need an absolute objective standard. Moral relativism is more in line with my thinking of morality.
Yet if moral relativism is true then you
cannot judge Harry by
your moral standards. Not to mention that falsifying moral relativism is simple as all I need to do is state that moral relativism is morally wrong, which causes moral relativism to be both morally right and morally wrong at the same time which violates the Law of Non-Contradiction.
Descriptive moral relativism is merely the positive or descriptive position that there exist, in fact, fundamental disagreements about the right course of action even when the same facts hold true and the same consequences seem likely to arise.[2] It is the observation that different cultures have different moral standards.
Even if that were true in the Dresdenverse, that only supports my position. Harry was in a culture that did not have a moral prohibition against his action, neither is there any reason for Harry to subscribe to your relative code of morality nor for you to hold him to that standard.