I had a similar event, with a kid on a skateboard flying downhill. No contact, but he dumped the board and slid a good ways.
I stopped and checked to make sure he was ok, and was surprised when he thank'd me and said that most people don't stop, or even slow down. Even admitted he probably shouldn't haven been doing that on a bus route street...sure looked like he was having fun though, so can't fault him too much. He just happened to be in my A pillar blind spot as I turned he corner!
Slow down, breathe, enjoy the ride!!