Canis is such an entitled prick, he legitimately committed a terrorist attack and attempted to murder hundreds of innocent people and now he's pissy that he's being given the option to get off scott free if he just gives up money that he never had and didn't know was coming to him, if he was really that pissed he could have taken the blame but had Arin say she was brainwashed then give her the money. Legitimately disliked him before but now I kind of hate him.
Bad people can't complain about getting taken advantaged of?
That's usually the reason why people become bad in the first place.
Him being unrepentant isn't much of a problem either, the justice system decided to take money over making him repent or suffer any consequences (his master probably set it up knowing it would end up like that), and as the inspector said, he was technically brainwashed since he was a child (and he's still a child).
He was just complaining about getting the run around even in this place and equating it back to the situation that lead him down this path in the first place (which is completely understandable).
Also it would be completely dumb of him to leave his sister alone with no guarantee of her safety to fend for herself (even with the money).