In a war considered high tech even by the standards of the early 21st century, Chief, the man who would commandeer the PBR used to transport Captain Willard in his mission down river to kill Colonel Kurtz, was himself killed with something as primitive as a spear, one apparently thrown by a montagnard tribesman.  It seemed that Chief himself could not believe it, his dying words capturing his own amazement and perhaps disbelief in regard to his fate: "A spear?!".