They chose not to take the way out because they knew they could doctor the investigation and go after the Pats.. if they anticipated the media brouhaha pretty confident they would not have released the initial information, that is where they lost control..
If they just relied on the IGL the questions would have remained, and for many the Patriots would have been guilty anyway, as ESPN et al would have fed anecdotal evidence to the masses..
The Wells report verified the outcome that the NFL wanted after it became a media feeding frenzy..
The easy answer would have been a "quiet" fine of 25K or something and everyone moves on, however they chose not to do that... this whole incident is not a very big deal, and there is no statistical difference for Brady on the road(balls controlled by the home team) and Brady at home(balls controlled by the Pats)... inow ball pressure means nothing. The NFL made it a big deal..
This whole incident is comparable to San Diego using stickum on towels or Minnesota warming footballs, nothing more than either of those two incidents..