Cass wasn't a man who was afraid of many things, but he was also not a fool and an angry man with a wand pointed at you, when you yourself had none, was undoubtedly a dangerous situation.
'You do not want to kill me,' he said quietly, because as much as he'd like to pretend that wand was lifted for just a minor hex, he also knew that even a minor hex might be fatal to him at this point.
That wasn't even factoring in that Montague was a Death Eater and might very well have killed before.
He pushed that thought aside though, not willing to consider it, and took the fact that Montague lowered his wand as proof that he wasn't all that bad. He couldn't be. He was just angry.
'No, I'm not, remember,' he answered simply, watching the back of Montague as he headed for the door. 'That doesn't mean that I won't always think of you as such, and if you ever pull your head out of your arse long enough to see that I'll be around.'
He wasn't sure Montague even heard as he watched him disappear out of the door, and as the door closed behind him, all Cass could do was sigh.