Considering how bad he got his teeth got kicked in and even descended into the dreaded state of "shadow self" for a stretch of time where he was blaming anything and everything (exposure, conditions, equipment, lack of sleep, dehydration, the fact that nobody else was dumb enough to be where we were etc) and nothing was coming out of his mouth but negative self talk, I was just trying my best to be positive and encouraging. I resisted the temptation of the "FU break" by getting going as soon as he caught up and instead hung with him and just tried to objectify the situation, laugh at the misery and take it in stride. It wasn't the time and place for a lecture on zone 2 training, but on the drive back I tried to subtly mention how I hike up a certain hill in town multiple times a week and haven't done burpees in years.
That being said, I'm sure he thinks he just needs to up the intensity and frequency more and he'll be good. Most of us have drank the interval training Koolaid at some point -its a seductive mistress.