I wouldn't ride with that guy because he sounds like a moron. But, liability was a big issue for AMC a couple of years ago. Not because of a lawsuit, but before, rides were always led with the knowledge that sometimes everyone didn't stay together, although we always have to have a sweep. The lawyers could not see the difference between leading a ride and a hike or x country skiing. We do have everyone sign a liability release. After 2 years of arguing, the executive committee said they would be "lax" in interpreting the rules for us. But, a lot of the cycling leaders quit. What we do is clearly state that if you go ahead of the leader, tell us and you are "off" the ride, and there is no liability involved for us.
In reality, there have been a couple of times that both my husband and I have told a couple of people to go ahead on the climbs because they were hammering at a pace that was not conducive to the group. When I had to do this, I was leading a hill ride that I was supposed to be the sweep on. But, my husband had a medical emergency, so I had to lead a ride on a 95 degree day, with about 2,000 feet of climbing (Lost Lake in Groton). I knew a couple of the guys could climb faster than me, so I appointed my friend's husband to keep them under control and wait for me and the rest of the group. It worked out fine, but it was sort of skirting the rules.