He couldn't answer

It was the attendant of the Bloodline Trial Office who warned about Roan and Frandin. When the two of them went there, they didn't ask to obtain the bloodline trial but about the security measures to go there. Not to mention that Frandin didn't try to take the Soul Power test either. It was quite unusual for someone to ask about these things without even being sure if they had the necessary Soul Power. Of course, Roan and Frandin's appearances were different at that time, so the attendant in the Bloodline Trial Office wasn't sure if it was them or not. Still, that was the best clue they found since Rean's group had disappeared from the city as well.