He did have a lot of hate, yes, but Severus is only capable of multitasking so many emotions at once, and his higher cause has found better targets for his loathing. A nod, and Velcro is released, though Severus wisely stays on the other side of the room in the event the dog isn't thrilled with its treatment. The wary way he holds himself dispels any notion of trust or cheerful embraces, but it's true he isn't simmering over with disdain, which ... may be unusual.

"What the hell have you done with yourself?" - No preamble, no why are you hiding or explanation as to why he himself is. Presumably neither man in this room has brains made of cotton and can bloody well figure that one out.