I thought about this for a while, and I think I can't agree with the question because of the word "should".
I don't think (as other posters have mentioned), that killing shoudl be his modus operandi. I don't think he should try to do it. But if it happens over the course of a battle, then the bad guy got what he deserved, and I don't think that reflects badly on ol' Webs. Sometimes the people trying to kill you get killed. And that's fine.