He walked away several times it looked like, and then after dude punched and pushed him up against the wall he gave an open handed push in self defense.
He honestly should have walked out after that. I understand the frustration but man, that's the shyt that gets you in trouble every time.
Depends on how good his lawyer is I guess, or if the old dude said he had a weapon and he feared for his safety still.
To answer the question tho, he was in the right when he defended himself, but fukk kickin the old dude when he is basically out from a single push