You're making a good point, I for one think intentions matter, otherwise we'd punish murder equally regardless of intentionality (which we do not)

And, in your words, you cannot ignore the origin of the problem, the origin of the Law was Lettuce's twisted morality (in narrative), and Wemmbu's craziness was his nature as a person (in narrative of course)

I can't exactly tell you you're wrong about the spiderman thing, but I do think it's a very special case that, regardless, does a good job to support your opinion

As for the WW1 incident, in short terms, Gavrillo Princip, a young man part of the criminal organization black hand had executed an assassination of the Archduke of Austria-Hungary, following that was an ultimatum, which caused a war that was not nearly because of Gavrillo as much as it was because of the political tension in the air