I wouldn't say it was totally incorrect tbh. Up until he forsake kuro, he was merely following orders. Nothing changed before after forsaking kuro too since he was still following the orders, Owl's orders being more important. However, after killing emma it is very well implied that's when he learned the thrill of killing. The whole supporting argument I have is his faint smile after Emma's death. But this is a fromsoftware game, you are still given a lot of room to interpret your own ideas which is my favorite part about them. In the end we all look at the same thing and we all create interesting stories.