I have discovered over the weekend a ruling from the R&A I received twelve years ago which predated the relatively recent ruling I posted above.
........the Committee can make it mandatory for a tee shot to be played from the astro-turf mat, however it would not be possible to require the player to stand on the mat.
It is the damage caused by the club as a result of a stroke that is considered to be the problem which causes the damage, rather than the player's stance on the teeing ground.
I have in my notes that the person who made the original ruling was aware of the later ruling (which I didn't receive directly). I understand the last sentence was the issue.
