I think these rulings are conflicting and confusing. Notice the the phrasing:
(A) - Since the receiver possesses the free kick BEFORE HE touched OOB, with the ball inside the SL plane, he is considered to have caused the ball to go OOB. I can understand that. If R runs up, catches the ball while inbounds or airborne having never contacted the ground OOB, then steps or lands OOB, I agree he has caused the ball to be OOB. I admit the "ball inside the SL plane" is confusing. Does that mean if he's standing inbounds and catches a kick which is outside the plane, it's dead? I think not. I think he can advance it.
(B) Since there was no touching by R prior to the PLAYER being OOB, K has caused the ball to be OOB This seems to imply that if the player IS OOB when he touches the kick, it's a free kick OOB. What is different about that and the OP?
Also, 4-3-1 does nothing to clear up the issue. If anything, it supports the assumption that a ball in the field of play touched by a player OOB is considered to be OOB.
4-3-1 . . . When a loose ball goes out of bounds, the out-of-bounds spot is fixed by the yard line where the foremost point of the ball crossed the sideline. When the ball becomes dead in the field of play because of touching a person who is out of bounds, the out-of-bounds spot is fixed by the yard line through the foremost point of the ball.
This is very true, especially on a scrimmage play. If a fumble rolling along in the field of play is touched by a player straddling the sideline, the ball is dead immediately. It is considered OOB at the spot, and belongs to the fumbling team, because it has never been possessed by the player it touched. In my opinion, the free kick is the same way. A free kick in flight, touched by a player who is OOB, is considered to be OOB at that point. Since R is OOB, it's impossible for him to have possessed the kick before he touched OOB. Therefore, it's a free kick OOB.
One more thing and I'm done. If I'm not mistaken, this casebook play is the only place in the rules where the sideline plane comes into play in regard to possession. At no other point do we make a determination whether a ball is OOB based on it being inside/outside the sideline plane when touched. it's true the plane comes into play at the goal line, but even then we have the goalline extended to make it clear the position of the ball over fair/foul (for lack of a better term) doesn't factor in as much as the inbounds status of the player. This is not baseball, where the position of the ball is vital in regard to fair/foul. In football, it's the touching of the ball in relation to inbounds/out of bounds that matters. A ball that is inbounds is considered to be inbounds until it touches something oob. Touching something oob does not change the status of the ball. A pass is still a pass, a fumble is still a fumble, and a kick is still a kick.
I can't seem to make sense of this any other way.