Lacking guns and even bows, they could hunt only by digging traps or pursuing prey across the mountains until the animals collapsed from exhaustion. It's interesting that they stumbled on the persistence hunting technique so naturally. Indirect evidence to support the Endurance running hypothesis ( http://en.wikipedia.org/wiki/Endurance_running_hypothesis ).
Between the barefoot hunting and the persistence hunting, this story seems like it's tailor made for Born to Run.