it is a KO, but no advantage was gained from knocking it on, ko is immaterial .. play onSH reaches into the ruck to grab the ball, knocks on while the ball is still "in" the ruck.
Oppo cant play it - ball in ruck.
SH hasn't been disadvantaged.
presumably that IS a KO?
Obviously I am recommending a trial, not an immediate Law change, to test it.
my idea is to make a KO more like , say, accidental offside
player is accidentally offside if the player cannot avoid being touched by the ball or by a team-mate who is carrying the ball. Only if the offending team gains an advantage should play stop. Sanction: Scrum
Knock On - When a player loses possession of the ball and it goes forward, or when a player hits the ball forward with the hand or arm, or when the ball hits the hand or arm and goes forward, and the ball touches the ground or another player before the original player can catch it. Only if the offending team gains an advantage should play stop. Sanction: Scrum