Klautz saw the girl as just a pawn that had once further Kishiogakure's interests and now would be furthering his own.
While it was true that the girl had once attacked him in the bonus stage, but Klautz barely held any forms of strong feelings towards the event. One must remember that Klautz couldn't even recall the girl's name. That was the kind of importance he gave to the girl. Absolutely nothing.
Sense of Justice? Klautz had none. He didn't care about the deaths of the newbies either. His own interests took priority.
'Let bygones be bygones.' Klautz thought.
The girl was just a fish that had already fallen in Klautz's trap. Now whether Klautz fries it or keeps it at the aquarium was his decision to make.
