You see this is the problem. This is not, at least I can't find it, in the law book. So what is your law justification for assuming it?
I will not deny that I would like to see the IRB clarify when exactly the tackle is over. It has been done (to a varying degree of success I admit) for the lineout, ruck and maul. What we have is a defined situation as to what is a tackle and tackle situation is and what players have to do when there is a tackle. Outside of that we have to make some assumptions; one being that outside of definition and actions permitted by players we have an open play situation. Without taking the position that I have outlined we would have an untenable situation for the referee. What would you (or any ref) do in the following scenario?
A tackle occurs. There is a very close support player. The ball carrier pops the ball to the support player. The ball only travels 600mm up from the tackle. (Easy height to catch.) Does an equally close chaser/defender then have to allow the support player to run two paces before tackling him because he is still in the tackle zone? According to some according to some previous comments, the defender would be offside. The defender cannot intercept the ‘pop’ and has to avoid the ball? I personally have never seen a referee prevent or penalise such actions. I believe the only thing a referee can do to keep credibility would be to interpret the law in relation to the tackle as I have outlined.
The whole problem revolves around the scenario looking wrong rather than being incorrect.
What about at junior level? Some players aren’t a metre tall in the first place!
Any law reference? No, my opinion has been based on discussing the matter with a couple of well-known international referees a few years ago. I’m desperately trying to find the written communications I had with them about the matter but since then I have changed computers several times and I cannot find the dialogue. That is the reason why I have delayed my response.