I agree it’s Page. But Trump didn’t know who it was. Though he probably knows now.
Trump gets to see the un-redacted documents, and he can declassify anything. So, no, it wasn’t Sessions or Paige, and though I’d bet it was Steve Bannon, I wouldn’t be surprised if it wasn’t.
I’m not too up on Page, but my recollection is that he’s done this spy for hire type gig before.
Truth be told, I don’t care about Page even if he is the spy. The people who sent him, however...very interested in them.