It's still murder, because the sentience that was inherent to the flesh, that was pushed aside by Amy's consciousness, was destroyed. That sentience was still in there somewhere; it just wasn't in control. That was the entire point of the two-part episode. That intelligence was living, feeling, and thinking. It might not have been aware to experience the pain of death, but it still died. It still deserved to be treated as a person and not summarily executed.