I don't know what Dad was. He was Dad. I suspect that between the classes neurotypical and Autistic lies a third: Robots, in the true sense. Bigger than neurotypical, but without the scary power of a full grown Autistic Mind. But Robots are vulnerable to slavery. Eventually the Paradox was formed: The Allsup Family. It is no meaningful mathematical likelihood of existing, yet John and Heather are proof that it was. But they can't see John, so Heather is all that's left. Heather is the public facing proof that Dad was R_David_Allsup, a robot.