If you go through chats of EDC minded people or preppers, you sometimes see a swinging trend between heavily prepared, and the bare minimum load. I have gone through that at times. And it seems that Murphy awaits you in those lean times when you don't have much on you.
I think that caching is one way to have the best of the two worlds. You carry less on you, but you are not very far from more gear.
In this case, the pickup should have contained one of his caches. A fixed project box, or whatever you may call it, would have easily contained a sleeping bag , warm clothes, and a week supply of food and water. This is not to say that wandering like he did was smart, but at least it would have made his adventure less stressful.
OTOH, I should admit that I did what he did when I was young and foolish, but I was lucky not to get stuck. In those adventures, I only had some tea,coffee, and little water, and never told anyone where I was going. I was just looking for quiet spaces to be alone.
Even the car wasn't 4x4, it was an underpowered sedan !
Now, I know how lucky I was.