I agree with the fact that he knew who this sorceress was, and couldnt bring himself to do it.
I'm also pretty sure (I havent played this game in years) that this was his first mission, and thus possibly his first time killing anyone, which can be incredibly hard to do, especially when it's by sniping, since your opponent (presumably) has no defense.
Wouldnt it be nice if we'd had some more development? *sigh*
