While the rural counties of CA can be "may issue", as a practical matter the entire SF Bay Area is "no issue". The guy is young, and clearly able to fight. Why would any unarmed citizen put themselves in danger by "going after" him.
And, even more pertinent is the question of what does a citizen who catches him do? If we beat him up, we have assaulted him and will be jailed for years. If we follow him, we will end up in a crappy neighborhood where his homies will assault us for just being there.
If I had been allowed to carry while I lived there and had seen the incident, I would have followed him to at least get the license of his car. But, with no protection, he would have made an easy target of an old white man.
The woman was obviously in no further danger from the perp, and anyone who "went after him" as you suggest would have just brought legal trouble on himself.
They could have "gone after him" long enough to get a cell-phone photograph. Post it anonymously, notify the police, and get the victim to identify it. It's not that hard.
Which neighborhood would that have been? It would have been quite a long run.