I did tell him right before the ride I was in pain, recovering from a knee injury, was under doctor's orders not to ride more than 30 miles, not to ride hills...and he then proceeded to lead me on a 38 mile hilly ride.

Talking to him is an exercise in futility, as I have pointed out several times above. There is no one right answer to every situation- sometimes talking to people directly causes more trouble than it solves.