but if his foot had remianed on the ground when he made the pass, he would have been OK, right?
If his foot was still on the ground, technically he is still in the playing area so yes, he would be OK.
Think of a player who is standing in the FoP near the touch line and reaches across the plane-of-touch to catch a ball. The ball is beyond the plane-of-touch but the player is still in the FoP. If he manages to pass or flick the ball back into the FoP, it is play on.
If he attempts to catch the ball and it hits his hands then drops on the ground in-touch, he has put the ball in touch, not the kicker.
Once a player is in the air and his body is beyond the plane-of-touch and the ball is beyond the plane-of-touch, it will be basically impossible for him to catch or flick the ball back and land with both feet in the FoP. Feet off the ground, player and ball beyond plane-of-touch, ball is in touch.
I know there are some who will disagree with all of that but that's the way it currently is and following the other 165 + post thread, I don't intend to debate it all over again.
Can't wait for 2017.