That is where I thought you were heading with this. In addition, there are major gaps where we do not know his whereabouts, no one has seemed to see him, and there are no pictures of him.
For the ED, I also think the same thing. I have kicked around some (far-fetched) ideas such as smoke inhalation and trying to hide from it in his tent. I have also speculated about him having a condition leading up to starving due to a form of paralysis (stroke, seizure, coma, tetanus) and being technically alive but ultimately dying from starvation.
A few (off the wall) theories I won't discuss to deeply is the possibility of toxic fumes instead of smoke. There is also the possibility that a very foggy day could have disorientated him very badly and he didn't realize how much time had passed or where he was. Eventually he stumbled back to his tent, ate and drank something, and then succumbed shortly after.
A (slightly ridiculous) theory of mine is that he may have been (literally) scared to death. In this scenario, MH may have been surrounded by wild boars, Florida panthers, bobcats, (probably not bears in the summer) etc. That is a little dramatic sounding to be scared to death from animals making intimidating sounds (such as boars burrowing), but what if he was deathly afraid of (lets say) snakes (a very common phobia) and woke up with one (or more) on his chest (or other areas such as the place that was mysteriously bleeding). When scared to death (literally) your adrenaline glands kick into high gear and completely take over your central nervous system. This could have lead to him trashing the tent to try and get the snake away, and this his system went into total shock. The overload could have completely disabled him until he starved to death. (Super wild speculation, but hey, I have an over-active imagination).