That's not true -- Stoudemire and Diaw have a 1 game suspension plus a fine coming to them only if they are determined to have left the vicinity of the bench during an altercation. The Commissioner (and Stu Jackson) get the final word about whether the rule was broken -- I could see that they might conclude that it was not; I could also see that they might conclude that it was.
The question, though, is whether the rule was actually broken; it's hard to tell given the vagueness of the terms used to define the rule.