I mean, he is the greatest player in history, he definitely can feel if something is odd, it's not the first match he loses.
Bobby Fischer was one of the greatest players in history, and he was EXTREMELY paranoid.
No, that's all he has said thus far. You don't have the faintest idea what he "can say". In fact, Magnus hints that he has more to say, if GM Cheatboy gives him permission to do so without threat of a lawsuit.
I imagine Magnus is telling the truth about that.
Exactly, and if he really wants to, he'll just give Magnus permission to say what he needs to say and they can discuss the matter transparently.