Cheating in rugby games is a nice thread digression even though "they do it and we don't" is a bit silly.
Current day cheating has evolved to a higher form: it's like a virus that changes into something nastier a few generations down the track.
I used to rail against McCaw for tackling and sliding down, even throwing himself down, on the "wrong" side of the tackle, which he did better than anybody else. The law crackdrown stopped that obvious stuff and now it's more subtle: the oh so accidental flop - even a bogus getting away like Goody Two Shoes flop, faking compliance and slyly obstructing rivals as it is done. One could even give a mark like the diving judges do and give extra points for degree of difficulty.
It's getting so the ref has to take the view: "If there was a snake present, could he have avoided being there?"
Still, it's better than it used to be before the crackdown.
Not quite to the point but I am surprised that commentators keep on asking how a player could be expected to roll away from a certain situation, but it's the wrong question. What they should be asking instead is: why did the tackler put himself into a position where he couldn't roll away from?
Sometimes a tackler has no choice in the matter, but on more occasions than we think he decided to land where he did which made him vulnerable to being trapped there. Often he could have displaced himself more towards his own team or to the side just before hitting the deck and still effected the tackle.
I think that referees know that some tacklers could never have rolled away but that some others could have if they took action before they hit the ground, without any danger of them having to release the tackled player to do so. Sometimes they see tacklers wrestle themselves to be in the wrong position as they fall.
Referees' responses to the matter reveal another convention that they use: not sanctioning against a law infringed (not rolling away), but sanctioning the underlying reason for the infringement (putting themselves in a position from which they could not do so, beforehand.)
There are many conventions that referees use and most, like the convention of allowing the skew feed to the scrum, are harmful, but this convention, like a couple of others, is good for the game.
But I have digressed from the digression.