I took from Tony Archer 'its only a penalty try if the player has control of the ball' to mean......a player will have to be holding the ball when illegally interfered with.....that scenario ......only allows for dirty tackles that cause the playerto drop a ball.
As I said, they are creating problems for themselves. I reckon bin it. Only used when Captains disagree with a decision, each team has one review per half. Refs are paid to make decisions, they have two on field, make a decision.