The original rule was introduced because of Matthew Primus. He was huge, and would just take the ball out of the ruck, hold his arms up and then handpass when he felt like it, no matter who was tackling him. So they changed it so that if any sort of tackle got laid on a ruckman who'd taken possession out of the ruck it became an instant htb decision.
Now they've reverted, but the onus is still on the player with the ball to dispose of it legally. And dropping it, handing it to your mate, or putting it on the ground and pushing it away are not legal means of disposal. I think the umpires need clear guidelines on correct disposal, particularly when the ball is taken out of the ruck.
