Quote: TheElectricGlidingWarrior "I'm not sure that's correct. Players can and do knock on after the tackle is completed (such as when regaining their feet) and the ball being dead does not affect this.'"
By the letter of the law, it is correct. The evil "interpretation" is where the knock ons come from. For example, walmsleys knock on on the turn over vs castleford, by the letter of the law, wasn't a knock on (the ball wasn't in play) - but interpretation/ logic/ common sense says he shouldn't be rewarded for stupidity.
In this instance, the ball was dead, the player was injured. It was interpreted the injury affected the play (aka was the reason the knock on happened) and thus should just be a play the ball (just like players having to return to the point a tackle is completed now)