Well, that's a helpful comment. It certainly explains why players fudging their die rolls is inherently wrong.
I think if you ask most people, they will agree that consciously and repeatedly breaking the rules of a game is inherently wrong. The burden of proof falls on the one making the outrageous claim, and in this case the claim to be proven is that "one person breaking the rules while all the others follow the rules is an acceptable way to play D&D".