Paul doesn't flee because there are machine guns sweeping the ground all around him. His reaction is to get as far away from the body as quickly as possible.
So I crawl away to the farthest corner and stay there, my eyes glued on him, my hand grasping the knife--ready, if he stirs, to spring at him again. But he won't do so any more, I can hear that already in his gurgling.
I can see him indistinctly. I have but one desire, to get away. If it is not soon it will be too light; it will be difficult enough now. Then as I try to raise up my head I see it is impossible already. The machine-gunfire so sweeps the ground that I should be shot through and through before I could make one jump.