I wondered if this would ever appear over the horizon, as there have been some troubling cases in recent years, where gang members have been found guilty of murder, despite not touching the victim, or going near him. I think the recent case was where somebody wasn't even in the same room.
I don't know how much it will invalidate previous cases, or inhibit future ones, but I guess there will have to be a stronger case, to prove murder, than just loitering.