Would you PK an opposition player who brings the BC - and only the BC - to ground?
No.
if the bc has been brought to ground alone then the maul has not been collapsed ?
True.
We are dancing on the heads of pins here.
Yes we are.
And for Browner: People who throw bricks through store windows and rugby players who willfully obstruct are not innocents and should be punished for their crimes. I'm already regretting starting the analogy.
Do I see that EVER happening?
I reckon that it happens (see the OP) but discerning cause and effect is another matter.
The issue could be moot anyway. I can't speak for other referees, but for me, in the case where the ball or the ball carrier ends up on the ground, I would want that ball available quicker than greased weasel poo or I'm blowing the maul up, even if everyone else is still on their feet... 17.6 (g) backs me up on that....
I'm not familiar with the properties of 'greased weasel poo' but agree totally with the sentiment.