You're making assumptions that might not necessarily be true. Trump's thing is control, being the guy who has his hand in everything. Based on that, it's difficult to believe that he allowed a wall (no pun intended) of plausible deniability to be built around him, that he didn't know or even orchestrate who was saying what or meeting with who on the other side. Delegation is not Trump's thing.
That's what brought Nixon down with Watergate. Personal involvement rather than having his people take care of things and intentionally keep him out of the loop for the sake of plausible deniability.