Was your buddy able to descend ok slowly, or did you physically need to assist?
I did the entire trail yesterday and it seems you are pretty screwed if you get sick or injured way up there.
The scariest part of the whole scenario for me was when he looked me dead in the face and told me he needed my help, and didn't know if he could make it down without it. I kinda half thought maybe he was joking or testing my friendship/loyalty to that point.
He was pretty good on his own, but I had to give him a hand around a lot of the ice that had formed through the switchbacks. Once down at Trail Camp, we got water in him, and back down around Mirror Lake he was asking for food. After Mirror Lake his pace and attitude picked up greatly. He was a trooper about the whole thing.