Well they have to cover all angles I suppose.
It sounds to me he got off his nut, which a couple of videos confirm, then he's gone back to some after party with two fellas up in the mountain, probably for some more gear. Then at 8 in the morning he's decided to go back to where he was staying. A lady said he asked her what time the bus is and she said 2 hours. I think him being off his nut has probably thought he isn't waiting 2 hours and stupidly attempted to walk, possibly for a bus stop further down to kill some time. Of course, it's mountainess terrain, its easy to get lost and very difficult to navigate without skill, experience and necessities, which he doesn't have.
I really think that's the top and bottom of it. Him calling his friend saying he's lost, plus asking a local lady when the bus is and then later wandering off, I think it pretty much backs it up.
There's a lot of crazy internet conspiracies on Facebook about this case from people who have watched too many Netflix documentaries and there's also people calling people he was with over there drug smugglers and things like that, which they should be very careful about because there's no evidence of that as it stands.
In my opinion its a case of the ol' Occam's razor. The simplest theory usually being the biggest possibility.