I was just checking the forum to see if I could find an update o He was experiencing overwhelming lethargy and had lost some coordination. He also seemed foggy, or perhaps mildly confused, but was still trying. One of his party was concerned that he might be suffering from exertional rhabdomyolsis.
exertional rhabdo would be a long shot
Going by the maxim that "Sickness at altitude is altitude-sickness until proven otherwise,
" this person exhibited several signs and symptoms of HACE : "lethargy," "lost coordination" (otherwise known as ataxia), "foggy/confused." Patients can go straight to HACE without initial AMS or headache, whether real or unrecognized. There are other situations that might mimic this, such as a diabetes patient with insulin-induced hypoglycemia and of course that can occur at any altitude.
As we have discussed here before, HACE is unusual at 11,000 ft but it happens anywhere above 8000 ft, the threshold of altitude illnesses. I hope the person improved with the rescue. It would be educational and instructive to know more.