User blog comment:Longlivemerlin/Merlin 'The Diamond of the Day Dialogue Teasers' UPDATE 3/@comment-5253758-20121220192800

Sorry for too many posts! "If I'd wanted him dead, I'd have put a sword in his gut."

This could be Morgana about Merlin. She does not kill him when she has the chance and maybe that's how she explains herself to Mordred or someone else.