The sequence of altered mental status and ataxia (stumbling, uncoordinated gait) does not matter. And/or by definition, although, unknown to us, a "premorbid" non-altitude condition could be a factor.
Just to follow-up on my own comments here....
That fact that he was able to continue on up, even with assistance, and return, suggests it was
not HACE ( even though the criteria were met) but rather a premorbid condition.
Morbid does not mean the same as mortal. Premorbid just means he brought an illness or condition
into the setting and was aggravated there (high altitude). I wonder if a premorbid neurological condition was in play. A common one might have been the use of sleeping pills, alcohol or other agents the day or night before.
I think the fact is we will never know for sure. All I can share is my observations. And my observations were made after trail crest where my own thinking was somewhat impaired as well. I did not have any problematic AMS symptoms but I did have slight shortness of breath and a slight "airy" feeling in my thinking. So my observations probably weren't as sharp as they might have been at lower elevation. Add to the fact that when I made them, HACE was not even on my radar. Although I have come across the term before, it never came up in connection with Whitney during my preparation. I think when I read "Into Thin Air" there was some reference to it.
One of the conclusions I have come to is that prior to the hike I had in my mind equated hiking safety with the SCUBA "Buddy system" and in retrospect I think that is the wrong way to look at it. When I obtained my SCUBA certification the most important thing I learned is that you always dive with a buddy and that you NEVER leave your buddy. Not only was that driven home during my class, but since then I know two people who have died SCUBA diving and in both cases the person was separated from their buddy. The concept is so deeply ingrained in my thinking I actually changed dentists after striking up a conversation with mine about SCUBA diving. He rather nonchalantly told me that his wife was his normal diving "buddy" but that she was slow and that he would normally leave her behind after several minutes during a dive. I figured if he was that careless with his own wife's (and his own) life, I did not want him working on my teeth with sharp instruments.
But after hiking Whitney with my group I realize now that simply does not apply. In SCUBA you usually know your buddy well, and you both have the same training and same ideas about the buddy system. Also if your buddy gets in trouble and needs to ascend during a dive the cost of ascending with him is much less than the cost of descending during a climb. In other words if you abort a dive, you can solve the problem and then resume the dive. This is unlike the desire to summit where descending for your "buddy's" safety means the summit quest has ended.
You also have the added group dynamic. Not just a single buddy who you know and presumably trust. We did not pair off at the beginning of the hike, so it felt like we were all equally responsible (or not responsible) for every member of our group. That makes the decision much more complex when it is time to make it. I kept going around and around in a feedback loop of thinking that this particular guy was not my responsibility since I did not even know him prior to that day, and that the person who invited him and actually knew him should be the responsible party to then coming around to thinking that regardless of that if something was to happen I would STILL feel some amount of responsibility if someone in my group had a serious problem. And if that became a fatality I would carry it for the rest of my life. My next sequence of thoughts was invariably that I was being overly dramatic about the whole thing. Then I would realize that is probably exactly what the John Likely party felt when they left him behind (no judgement here, I actually gained some understanding about that situation). And so back to square one I would go.
The OTHER important realization i have come to is the syndrome of a group of hikers of different fitness levels hiking together. It seems to me if hikers of different abilities (or pace) begin a hike together it starts an accordion effect that actually takes the difference in abilities (which may be small) and in a cascading nature, exacerbates them. Because what happens, or at least what happened in our group of 6 was that 4 of us hiked at what we thought was a comfortable pace. But that pace was just a little bit too fast for the other two.
So what happened? Well we would slowly build a gap between the front four and the back two and allow that gap to expand until we were in danger of losing contact with two stragglers. At that point we would rest while they caught up.
Meanwhile I imagine the two stragglers started out at what they thought was a comfortable pace for their abilities, but then found that after a period of time they were falling behind. I imagine at that point they would have attempted to increase their pace, to the fastest pace they could maintain. Which was probably too fast for comfort. Yet they still steadily fell behind.
When we rested they had to continue hiking and the fact that they we were resting once they saw us would have probably been an ego hit to them as well, only making them push a little harder. And what happens when they catch up to us at our resting location? Well, for one the lead group is by now well rested and ready to go. But the trailing group is in need of an EVEN longer rest having pushed themselves to their limit to reach us and not "waste our time".
Now as bad as it sounds I am sure we showed signs of being ready to go and wanted to take off as soon as the trailing group caught up. Usually they'd say something like "you guys go on ahead and we'll catch you at the next rest" and the lead group would leave with the same thought. Believing they were being polite and helpful.
But what is really happening? Now the lead group is progressing, well rested, at the same fast pace or maybe even slightly faster while the trailing group is sitting still at rest. They are aware of that too and as a result are going to start hiking again at the earliest possible moment, and probably not after they have gotten an adequate rest. If you think about it, they should actually rest even LONGER than the lead group had waited for them because they are obviously even more fatigued having pushed harder. But if they did, by the time they set off again the lead group would be even farther ahead of them than they were before they rested in the first place so they would either have to stop again to maintain contact, or increase to the gap to the point where contact was no longer maintained, effectively "leaving the trailing group behind".
This cycle repeats up the hill in my opinion until the trailing group just hits the wall (like one of our trailers who gave up after 4 miles) or until they run into other problem like the remaining member of the trailing group who AMS and possible HACE.
The sad irony here is that his slowness HELPED me (and the rest of the front four) and may have even contributed to my lack of AMS symptoms. Since I spent so much time waiting for him I was always well rested. And when I was moving I had no problem moving at a pace I found comfortable, knowing that even at that pace I was leaving the other guy behind and thus would soon be sitting and waiting again.
Had it not been for him and it was just the four of us in the faster paced group I have no doubt the process would have come into play between the four of us and separated us into faster and slower individuals/groups, and had I found my pace slower than one of my fitter companions I would have now been in the position of pushing myself too hard, and getting too little rest.
There must be an answer to this. Maybe the answer is better screening of your hiking partners.
