While Stan is waiting for Kai by the mother and sees the boy in the sand, there is a cut to a close up of the body, and just before it cuts back to Stan, he is seen climbing the dune. This shot is used again once Stan has walked near to see the body.
Near the beginning, 790 is driving around on his buggy. Previously, he had crashed and tumbled off the buggy while chasing Kai and has no means (or limbs) of getting back on it.