The confusion of the moment doubtless resulted in the deaths of many of the Lamanite prisoners, but many of them also escaped. With no one to guard, the Nephites returned to assist in Cumeni.
Helaman concludes this part of the story by declaring that Jehovah had preserved them. Certainly, the nearly miraculous return of the guards was an important part of their eventual defeat of the new Lamanite army at Cumeni; it was seen as evidence for that divine preservation.
There is no chapter break at this point in the 1830 edition.