Despite Mr. Oigarden's article, I still would hold that solo diving, although not rare in the cave community, is not generally recommended or taught in the curricula of the major agencies. Rather than turn to diving solo to avoid time pressure, peer pressure and ego problems, and a dive pace you don't feel comfortable with, why not teach students to take their time, to feel comfortable questioning the dive plan, and to have the security to ask for a slower pace? Slowing my buddy down was one of the scenarios set up for me in my Full Cave class -- the instructor wanted to see that I would object to a pace that was too fast for me to keep up.
We are likely never going to know much more than we do right now about this particular accident, because we don't know and probably can't know where he went, or what resulted in delaying him until he was out of gas. We don't know if having someone else with him would have prevented a wrong turn, or helped at a point of confusion. I know that I have made two navigation errors (one in class, one out of it) that could have resulted in my own death, had I been alone and had no one to point the mistake out to me.
What I do know about Mexican cave diving is that the thing that's most likely to kill MOST cave divers down there is getting lost, and it's frighteningly easy to do, and is probably what happened to this unfortunate diver. I hope that, since he didn't have the advantages of other sets of eyes to avoid mistakes, he took every other precaution against going astray.
