 Why didn't Moran kill Harper?
I. Moran cut apart the yard-long monstrosity with a slash of flame. Moran, naturally, did not mean to help in the carrying out of the plans which would mean his destruction one way or another. From the viewpoint of the Nadine's ship's company, it was simply necessary to get rid of Moran. Moran disagreed, but he did not answer. Without rigid control of space-travel, any criminal anywhere could escape the consequences of any crime simply by buying a ticket to another world. Wherever the yacht landed, such a disparity between its documents and its crew would spark an investigation. Moran, at least, would be picked out as a fugitive from Coryus Three. And Moran was the extra man whose presence would rouse space-port officials' suspicion of the rest. Only people accustomed to desperate actions would have remained so calm when Moran had used desperate measures against them. Moran wondered, momentarily, what sort of world they came from and why they had revolted, and what sort of set-back to the revolt had sent the five off in what they considered a strategic retreat but their government would think defeat. Moran's own situation was perfectly clear. His victim would not be mourned by anybody, and somebody formerly in very great danger would now be safe, which was the reason for what Moran had done. But the dead man had been very important, and the fact that Moran had forced him to fight and killed him in fair combat made no difference. Moran had needed to get off-planet, and fast.
 Moran is not a murderer at heart. He only killed the other man to save a life.
 Moran is not a murderer at heart. He only killed the other man to save a life.  Moran would rather kill Burleigh. He is waiting for the right moment.  Moran is not a killer.  Moran likes Harper. Harper is a decent guy.