Yes. Happy to help you understand. Many homeless in SF are actually very mentally ill. They sometimes jump in front of traffic. This has happened to me a few times driving in SF. So the implication is that the bus driver may not at all have been at fault.
I'm not saying anyone deserved to die; the homeless in SF are basically not autonomous agents anymore. Right or wrong, it shifts it in my mind from "bus driver is at fault" to "nobody is at fault" (except the city that encourages themn to them stay drugged and on the streets).
So being homeless means that we shouldn't investigate fatal crashes? Personally, I don't think they should have to give up the right to not be murdered.
(Which is a bit sarcastic, perhaps, but people generally value the homeless less on various axis, whether they want to admit it or not, because when you hear "bad thing happened to man" you immediately want to know if that man could have been you, once you learn he was homeless the panic reaction subsides.)