Did Reuters simply watch vicious anti-gay attack and do nothing?

Great photo, Reuters.  It looks like those nature movies, where you watch the animal get attacked and killed, knowing that the documentarian can't get involved because nature must take its course.

Except that the animal in this case is a human being.

I'd love to know how many reporters simply treated this attack like a photo opp.

Which does raise an interesting journalistic ethics question.  Should reporters simply sit by and document crimes, especially violent crimes, without interfering?  What if they were about to kill this guy - would it still be okay for reporters to simply take photos and do nothing to help?