A Beyonder was allowed to leave the fleet? Without Danitz's deliberate explanation, Klein easily understood why he found it strange.
In a Nighthawk team, even the civilian staff would experience strict restrictions. Even a normal resignation would require them to sign a life-long confidentiality agreement. They weren't allowed to leave the Nighthawk team's area that they originally belonged to, and once they were approved to move to another city, they had to immediately register at the local Evernight Church.
From such rules, it could be seen how the officials treated Beyonders powers and related matters. A Beyonder who had drunk a potion wouldn't be able to leave their organization so easily.
Klein clearly remembered that Miss Justice initially had the means and channels to become a Beyonder, but she didn't attempt them. The reason given was that she didn't want to lose her freedom.