It sounds to me like GGP knew that DeOrr was injured, then died. In trying to lend support to VDK's accounts (with VDK placing emphasis on really odd, seemingly unimportant points), GGP actually contradicts VDK. I think VDK was trying to get the idea out there that DeOrr was FAST. Like, look away and he'd be GONE. But, GGP, knowing that DeOrr was injured, (maybe on the way to the campground, just before, or just after arriving) tries to offer up an excuse for how he could have gotten hurt with the "falling all the time" and the "too big boots" comments. Because surely GGP thought, with all the searchers there, that they would likely find DeOrr quickly and see whatever injuries he had, so he was trying to explain that away in advance. But, in doing so, he contradicts what VDK was trying to emphasize about him being fast.
Also, injuries that GGP thought could be explained away as the result of a fall, sound like head injuries, body injuries of the blunt force trauma type. Not asphyxiation, stab wounds, gunshot wounds.
This is off track a little, but I just wondered if perhaps one of them ran him over. VDK talked about the truck a lot. But, I still don't see why they wouldn't call 911 if that were the case. The only reason I can think of that would keep a parent from calling 911 when their child falls victim to a true accident is if they knew they'd get in trouble for some OTHER reason. Something that would be obvious just by the police showing up there. It would have to be something so evident that they would avoid calling the police at all costs. The only things that come to mind are:
1. Drugs.. would have to be an apparent lab or grow operation OR they would have to be undeniably obviously impaired and couldn't hide it.
2. Signs of other trauma on DeOrr that would become evident and not be explained by the accidental injuries he sustained.
What else??