Board Thread:General Discussion/@comment-25517595-20150330011154/@comment-24674051-20150402141349

Rather than focus on Snow, let's look at David for a minute. We've seen him skewer several Black Knights on the show. Just in the Pilot alone, he skewered 4-5 knights between Snow's delivery room and the Nursery where the wardrobe was situated. He has many sword battles under his belt, Yet his heart was also considered "Pure" enough to go through the door. (and at point it was still HIS heart). So just killing someone is not enough to make a heart impure. I think intent is also considered. In David's case, he was defending his baby, or fighting against evil, or had some other motive that allowed him to act without making his heart Impure.

Let's look at the MM/Cora incident. Cora was power hungry and heartless. She was threatening to murder Gold, not because he was evil, but because She desired his power. Cora's motives were suspect (to say the least). Snow was looking to prevent Cora from gaining that power, even if it meant keeping Gold alive. She did what she thought was necessary, and she later had to deal with her conscious because of the methods she used. But here's the other thing. Snow felt true remorse and regret for what she had to do (and was justified in doing). Regina is only just now starting to really come to terms with what she has done, and maybe starting to feel a little remorse herself.