He's in a publicly accessible place for social gathering so it's not unusual for someone to approach him. There's no real, legal indication of Schilling staging an attack with his hands both down; when it comes to what's *usually accepted in court. While cocking the hand back like that, is virtually an attack (and not just staging, ie. getting in stance, hands up, etc.).
Ultimately, we can go back and forth and play lawyer vs. prosecutor on the facts of the case and how to interpret them.
Self-Defense is a legal concept (affirmative defense) that says your actions under normal circumstances would be considered criminal, but you had a reason for doing it that would make it ok. The burden of proof is now on the defendant instead of the prosecutor to prove guilt. This is different and must be understood from the start.
So if I was Schilling, I would try to take it to Jury trial and hope for a sympathetic jury (if the facts are on your side, ask for a bench trial, if they aren't ask for a jury trial...advice from many attorneys I've talked with).
If I was the Prosecutor for this case I would point out the following things:
1) Schilling is a trained professional fighter who does this for a living and also had many more options even if he did think he needed to defend himself. There was not an equal amount of force used in the situation, it was excessive.
2) Schilling admitted in his initial statement that he had a problem with the guy and didn't like him, so this was not a random encounter
3) Schilling was not in imminent danger, so the use of force wasn't justified. Schilling chose to engage and put himself into harm's way and created the circumstances in which force was used. Schilling was hoping for a fight and got one. Self-defense is a situation in which one party does not want trouble but is forced to protect him/herself. This incident involved two willing participants to the confrontation. I would link in "officer induced jeopardy" showing that even when LEO's create circumstances in which they are forced to use force due to their own actions, it nullifies whether the actual application of force was justified or not at the time of its application because they created the situation themselves. Exactly as Schilling did, he created a scenario in which he wanted to use force and got it.
4) Since Schilling was a trained professional fighter, he was not in fear of his life. In fact, the circumstances show otherwise. If he was truly in fear for his life, he would have kept walking away and not crowd into the other person's personal space to confront him.
5) I would point out that Schilling's own statement contradicts itself that he was in fear for his life. Schilling said that he was "in fear for his life and needed to defend it against the evil in the world". No where did Schilling say that he was afraid of Balboa.
If I was Schilling's attorney I would point out the following things:
1) Balboa was highly intoxicated and making racial slurs towards people
2) Not on video, but I would claim that Balboa was drawing back a fist and Schilling reacted.
3) They bumped into each other and Balboa yelled "hey". Schilling was just walking back to see what he wanted because it was so loud he couldn't really hear him.
4) If would TRY to bring in testimony that Balboa was a constant problem in the bar (this would probably work in a civil trial, but would not be admissible in a criminal matter because it would prejudice a jury).
Again, it would all come down to how the judge or jury interprets all of this together. And we could debate which set better supports our own ideas of what happened.