Dishonoured non-lethal

Has anyone completed Dishonoured the good guy non-lethal way? I'm curious about Havelock's betrayal with non-lethal playthrough. With the evil/lethal approach, he needs to betray you and kill the others to cover up all the bloodshed. But why betray you if all you did is knock out several hundred guards?

Because they knew that you would never let them control Emily for their needs.
Or everybody chose the "evil" path like I did :-D It's probably the only game I've played where it's considered evil to kill your enemies (instead of just knocking them out). Innocents were always spared (and even saved!) and Lady Whatever (one of the targets) I actually didn't even kill - chose the good option.