My personal experiences are only of value in the sense that I am a heavy rider at 240lbs. This may not be nearly as heavy as the rider you encountered but I ride my off road bike rather hard - not rail trail but rocks, roots, jumps, creeks etc. so not a friendly operating environment.

The suggestions of using a tandem hub and spreading the frame could help with strength issues if the bike can accommodate it. The single most important factors in wheel strength and durability are adequate and balanced tension. Most wheels come right from the factory grossly under tensioned. Additionally, when people true the wheels as they go out of whack, they don't pay attention to tension balance often enough. Essentially a wheel assembly begins it's journey towards a rebuild from the day it is built. A heavier rider can put more stress on the wheel and wear it out sooner than a light rider. In fact light riders can get away with far more imperfections in a build. But almost any modern name brand wheel components can be built into a strong wheel as long as you follow the basics - Decent and Balanced Tension.