Yeah, I think this is the toughest aspect for him after the Eclipse. She pretty much despises him in her sort of animalistic way, she's relying purely on instinct and, to her, when he strangled her he's "the enemy". I know it's been over a hundred chapters, but I'm still struck by the tragedy of what Casca has become.
Interesting, though, that the previous chapter hinted at a part of him wanting to kill her.
