Hands up all those who thought I was wrong, and that the try was fairly awarded!
Well, you're wrong folks!
It seems those who recognised that stripping the ball out was an intentional act and was therefore covered by Clarification 2011-4, while knocking the ball out in the process of tackling isn't, have got it right on the money.
I was one of those; it seems I was wrong.
It complicates the process somewhat, of course; if intentionality isn't an issue, then the decision tree is:
* Did the ball go forward from the PoV of the tackler?
* Did the tackler knock the ball from the BC's hands?
* If yes to both, then knock on; if not, play on.
The decision tree if intentionality is an issue is:
* Which way did the ball go from the PoV of the tackler?
* Did the tackler knock the ball from the BC's hands?
* Did the tackler intend to do so?
* If forward/yes/yes, then tackler knock on
* If backward/yes/yes, then play on
* If forward/yes/no, then was the tackler the last player to play it; if so, then tackler knock on - otherwise play on
* If backward/yes/no, then was the BC the last player to play it; if so, then BC knock on - otherwise play on
Leaving you with not just judging intentionality, but also (if there is no intentionality) making the precise judgment call (who last played it) that the clarification was intended to make unnecessary. The "rip", where the ball is pulled from the BC's arms, rather than knocked from them, is actually the easiest situation in which to make that call.
You also have difficulties with big hits from in front where the tackler goes for man and ball together, and the shoulder makes contact with the ball; if the ball pops out, how do you judge intent?
Lyndon Bray's explanation of the difference between this clip and the Chiefs/Stormers incident really doesn't clarify, either; he makes no reference to intentionality (so presumably the latter contact was also unintentional), but bases the distinction on whether the BC intended to maintain possession or to pass.