It would be impossible for anyone to legitimately claim he's the initial aggressor, since he objectively is not.

And when he jams his way in to her, she turns around and says something, and keeps on shoving? If this was to guys, that would have started something.

No it doesn't. It isn't extent you deem necessary. It is extent they deem necessary.

It isn't what I or the two involved in the incident deem necessary, it's what a reasonable person deems necessary. Given the disparity of force between the football player and the woman and the weak blow she landed, it's pretty hard to claim that full on decking her was necessary to prevent bodily harm.

Saying someone is weaker doesn't mean jack shit.

It does in the eyes of the law. Disparity of force is a significant cornerstone of American self defense jurisprudence. If it didn't, you could defend, in the extreme case, decking a toddler because they raised a force to you. Disparity of force caselaw is the reason you can't claim a toddler presented a threat, just like this guy probably isn't going to be able to defend himself against the assault charge.

You don't know if she might grab a bottle or glass off that bar.

Which doesn't change the fact that she didn't.

Someone throws a punch, you are not accountable for throwing one back.

Jails are filled with people that tried that line of reasoning.

Disparity of force? A punch for a punch isn't a disparity. It is parity.

Is a punch from a toddler on parity with a young, built football player? Is the punch thrown by the woman? The guy walks away unharmed. It's clearly not parity.

Yes, it does.

Ask a prosecutor if it does. You'll find out rather rapidly you're wrong.