No way. Humanity since the dawn of time has always had the potential to mob when things became dire. We still have it today, only it is more controlled via technology and rationality. This killing will not start anarchy. But it does have the capability to start a resistance against existing power structures, and that is what everyone is actually (consciously or unconsciously) worried about. We are only conditioned to believe that anarchy might ensue as that is the easiest way to instill fear of rebellion against the power structure.