I saw no evidence that he was "screaming wildly". Even if he was, that doesn't give anyone the right to physically assault him. If I was seated on the jury I would vote not guilty.
This is going to be a tough call. Usually you can only use deadly force to protect your life (or others) from threat of death or serious bodily harm. If the threat retreats then the justification for deadly force may also be void, even if the threat got in a punch. You also have to have clean hands yourself. It would have been better it seems if he had just recovered and filed assault charges. Better still if he hadn't harassed the family member over parking, if in fact he did that. At this point his only defense might be that he was disoriented from the assault and still felt threatened with further assault (passion of the moment plea).
He looked pretty animated is the moments leading up to the shove to me.
Guess it’d be a hung jury if we were both on it!