Chuck Kennedy - It would be nice if it was clarified in the rules...
What I was really heading towards and the reason I quoted curt was his last statement of that post was that it's a bad habit to get into, and leaves you open for being called on it. That's the same reason I asked about my stamped discs being legal. Not knowing ahead of time leaves me open to being called, which I want to avoid. He should want to avoid it as well.
As far as ChUcK's second question of should he be called on it? I think he should. If he's a pro player he should know the rules and not violate or try to stretch them. Maybe it is just a bad habit he picked up and if that's the case, it's one he should break. If nobody ever calls him on it imagine the drama to ensue the one time he falls on his face, THEN gets called on it. "But... but... I've been doing it for 3 weeks, and it wasn't a problem before. Really guys? I mean, I fell after my put went in anyways." Other possibilities are that he doesn't know that it's a possible violation, or maybe he just wants those ballet classes to have paid off.

All kidding aside, perhaps it's something he's unaware of...
I think the underlying factor here isn't so much the rule (or lack there of) so much as it is the player habit surrounding the rule. Although different, it's quite similar to the speed limit. Tell me there isn't a lot of grey area there. If the speed limit's 65 and you go 73 while passing by multiple cops in the median everything's good, right? Sure is. Right up till you get pulled over for 69 in a 65. Don't speed and you won't get pulled over. (note - just a non dg example. I don't care how fast you go.)
Moral of the story(imo): If you don't want to get busted, don't do things that you could get busted for.