He must've had really big pockets if he was supposed to be carrying the kind of stuff mentioned.
There's no way he had enough water in that temperature for that hike in a Camelbak. And no Camelbak I'm familiar with would fit "plenty of snacks", especially if he was also carrying the 10 essentials, spare socks, long pants and long-sleeve sun shirts (since he seems to have been foolishly dressed in shorts and a black T-shirt).
I think the classification of this hiker as "experienced" is wildly misapplied, given the extreme mistakes in gear, apparel, headwear, and decision to do the hike in the first place. These are novice mistakes.
If he was wearing a camera around his neck, he could have slipped, got hung up on something, and strangled?