He might have just hit something in the road. I bicycled a lot when I lived in Florida and they used to have these turn lane dividers that were basically upside-down metal bowls that were bolted to the asphalt -- no big deal for cars but enough to send a cyclist to the ground if he doesn't see them, like I didn't one night.

Right -- the danger is from cars. Wearing ahelmet is a rarional response to the danger. Although scooters are a lot easier to fall off than bikes since speed/momentum does not keep them upright.