The truth to that question is more complicated than such. There is no simple yes or no answer. If only there were, then many matters would have been easier.

"In part." There is no holding back the truth, no matter its complexity.

"I acted on a vow... two vows to be precise. One magically unbreakable, the other equally impossible not to honour, even if not due to magic..." Severus looks at his hands, a trickery of his mind placing the image of his old wand there.

"I had no other options than to ... kill him."