Maybe the reason the NFL didn’t do anything about it is that there was nothing to do anything about. Of course owing to the nature of PR they must investigate (or at least “investigate”) otherwise people will whine.
They are that knowledgeable and capable of due diligence, which is a large part of why the accusations are stupid. Because of what the league does to verify the balls the risk level would be extremely high for little if any gain. the game hasn’t been undermined even the slightest. Unless you choose to believe every idiotic accusation, and then it’s not the game that’s been undermined, it’s you.
And if you simple dismiss accusations based on you own perception??
Looks like even Rush is not as quick to judge as some:
http://www.freerepublic.com/focus/f-news/3248465/posts