The phrasing was a joking Simpson's reference, but Peyton Manning has always been a dick since his days in Tennessee. Here's a link that outlines what I'm driving at, although it does not do it justice:
http://thebiglead.com/2014/09/18/peyton-manning-1996-tennessee-lawsuit-trainer-bare-butt-mooning/
To me, the issue isn't that Manning acted like an immature brat in college. (If that was a heinous crime I'd be guilty along with many others.) It's how he refused for years to take responsibility for his actions, going so far as to claim in a book published six years after the incident that the woman in question was "vulgar," and insinuating that she largely made up the allegations. This got her fired from her new job and driven out of her profession. He was sued and later settled with the woman and agreed not to deny it in public again. Then, in 2005, he repeated his lie and was sued again. And he settled again.
Conclusion: asshole.
To add on to this particular story, not only did Manning do all of the things listed above he also wrote in his book (quote taken from the Daily Beast)
“Never mind that women in the men’s locker room is one of the most misbegotten concessions to equal rights ever made,”
Manning wrote. “When Dad played, there was still at least a tacit acknowledgment that women and men are two different sexes, with all that implies, and a certain amount of decorum had to be maintained. Meaning when it came to training rooms and shower stalls, the opposite sex was not allowed. Common sense tells you why.”
He also attempted to say that the mooning incident wasn't meant for that woman but was him mooning a fellow athlete...except the athlete denied all of that (also from the Daily Beast)
As to the question of to whom Manning wanted to show his ass, Malcolm Saxon, a track and field athlete who was in the room during the incident, wrote
a letter to Manning to say that no, he was not the intended moon-ee (as Manning had written in his book), imploring him to “maintain some dignity and admit to what happened… Your celebrity doesn’t mean you can treat folks that way… Do the right thing here.”
Throughout this ordeal and the HGH accusations, Manning doesn't seem interested in accepting responsibility or wrong doing but instead bullying people and throwing out insults to move the narrative away from the truth and what he did. Unfortunately because the media is more interested in carrying his water than actual reporting, he rarely gets called out for this petty behavior
There's also the media portrayal of Peyton which is this "aw,shucks" good old boy who just pulls up his boot straps, never complains, and makes no excuses when in reality that can't be further from the truth.
His press conferences after losses are a master class in repeatedly saying "I'm not going to make excuses but...." while constantly making excuses, subtly throwing teammates under the bus and trying to deny any responsibility for the loss (
http://usatoday30.usatoday.com/sports/columnist/lopresti/2006-01-15-lopresti-colts_x.htm, a very good example of all of this is in this article)
Conclusion: asshole. The vote is now 2-0 in favor of asshole and one of history's greatest monsters