Shootin' selfies on the other side of the yellow tape after ambulances had already arrived?  See absolutely nothing wrong with that.  Who's he hurting?  More to the point, he's also not hindering the first responders, either. However...

Taking photos or shooting video of the mayhem just moments after the killer's car struck down victims?  This certainly occurred--but I have seen no complaints about that.   The first frame of the oft-seen video clip clearly shows one gent less than 10 feet from a victim shooting away--and not lifting a finger to help.  Instead, he shoots OTHER pedestrians rushing to aid the injured (dying?) victim. And the man who's caught all this action on HIS phone is doing the same.  Not lifting a finger to help.  Are both these people--and likely others-- morally disfunctional?  Are they slavering voyeurs?