Board Thread:Questions and Answers/@comment-4623180-20120906134039/@comment-5253758-20121018115934

It was different with Agravaine. He was in a realy hard position and killing him was his only choice for Arthur to survive. If you see things from his POV you can realise that he never had a "thing" for Agravaine. From the moment he met him he did not trust him. Morgana on the other hand was his "loyal" friend once. I think her betrayal still pains him. He can see good in people and obviously he saw that Agravaine has no good in him. I believe he has lost hope for Morgana too but due to their past, maybe he can't bring himself to kill her... yet.