It's possible it's a forgery.

[It seems as likely as anything. He still thinks the forgery is a possibility, but as soon as Tsukiyama asks that question, he has an oh moment of his own.]

Kimblee-san was the one acting suspiciously yesterday, wasn't he? The False Seer should have used the opportunity to scan him in their dreams, but they didn't. Instead they chose Fulbright-san.

[It's a strange choice.]