I actually did my first non-instructed dive with a buddy I met through the same e-group, so I felt very motivated to give back.
I do think a lot of the problem here was maldistributed weight. He was diving a jacket BC with 30 lbs in the weight pockets, which he said was what he needed for a 7 mil wetsuit. I don't dive a wetsuit, so I couldn't dispute that. I think he was seriously out of trim, and probably overweighted to boot. But, given his gear, there weren't a lot of options for changing things around. I did put his tank as high as it would reasonably go.
I chose a very conservative dive site on purpose -- the deepest you can get, at high tide, in this site is about 40 feet. We dropped in 15 feet of water, which probably didn't make it any easier on him, but kept both of us safe with multiple descents and ascents.
I really love to teach things . . . I taught medicine, I've taught riding, and I'm really looking forward to passing along some of the incredible energy and time that people have put into mentoring me diving. But clearly, my mentoring skills could use some polish!