Here's a google earth screenshot of the area:
That's a great visual, Chevy. The area Akichow and I are commenting on is not quite halfway up the slope. If you're descending, you can see that you're hiking in pretty much a straight line for a while, then you have two sharp lefts clustered in the slabs, one a classic hairpin. Miss one of those and things can get dicey pretty quickly. Add in possible darkness, exhaustion, confusion and/or AMS, and it's not that hard for someone to walk right off the edge. Wouldn't be the first time.
What is mystifying to me is that it's now been 4 full days and no results reported from the search. The mountain traffic is summerishly steady and it's only 2 miles from TC to OC. The only other area I can think of in that stretch that might present a danger where someone could disappear - at least reasonably close to the trail - would be the ledges above Consultation Lake. Plenty of opportunity there, but that would take some pretty deliberate off-trail effort.
Wish we had a better idea of his mental and physical state, and what supplies he had with him, but we just don't know because, as has been pointed out repeatedly, he was alone when he probably shouldn't have been. I keep thinking of the "I Shouldn't Be Alive" episode where a solo backpacker in the Sierra wandered off-trail and fell onto a ledge, where he survived for a number of days before being rescued. We can only hope this guy is as lucky.
