Coriantumr and his men are technically victorious, but only because they still have life left to walk away while all others appear to have died. The telling of the story makes it appear that Shiz arises to give battle just as Coriantumr and his men are leaving. Yet the next verse tells us that Shiz is in pursuit.
It is more likely that Shiz and some of his men recover enough to pursue. Had Coriantumr and his men had any advantage over the also weak Shiz and his men, they would have taken it immediately. The pursuit suggests that the reality was some time gap, and that this description is again given to heighten to suspense of the story.