Do you realize that there are laws about making statements about securities positions, and any intent to buy or sell, in public interviews? Stating something that isn't true in a public interview is considered to be securities fraud.
I have no doubt that Ackman is telling the truth on this one. He has had enough trouble with Icann and the related SEC investigations, some of which may still be active. He isn't stupid enough to lie about this and bring more SEC attention to himself.