That is akin to sniping.
Find yourself a good place to hide and wait?
Sorry mate, but this voyeurism, not street photography.
Having the balls to get up close and personal to take the shot in the first place is the whole point of street photography...
Probably could be better said.
I'm not a big fan of "sniping" or "voyeurism" but in the quoted context, they're inappropriate terms. Grieving people can be sensitive, and there is no good reason to appear to possibly disrespect their rituals.
As for what is or is not "street photography," there are as many definitions as there are people with cameras. Generally considered it can be characterized as candid photography of people in public places. Beyond that, it's all up for grabs. A father at disneyworld taking pictures of his kids engaged in horsing around with one another can legitimately be considered street photography. Bruce Gilden jams a camera and flash in someone's face on the street, captures a startled look, and it's considered street photography. It's all over the map, and we get in trouble trying to define it for others.
Finally, balls are not what it really takes to get "up close and personal" in street photography. The first requirement is a care for other people and a desire to validate their lives. We are not alone, or as Donne wrote, "no man is an island," and our connections with others is, I think, the most powerful driving force for good street photography. Like asking for a first date, our early efforts at photographing people we don't know may be nerve-jarring. If you do it for the right reasons, eventually it becomes comfortable -- perhaps like the familiarity of a marriage.
There is an iconic image of protest during the Vietnam war (maybe from Kent State) where a protester puts the stem of a flower into the bore of a soldier's rifle during a confrontation. Perphas it would be equally helpful for street photograpers to tape a flower on our cameras. At worse, it might increase the smile quotient.