This is just wrong. You cannot just leave your kid with some random employee. I know it can feel like Uber or Lyft drivers are your friends, but they are not. In fact, they are very close to being criminals. The only reason anyone drives for those companies is because they've screwed up every other opportunity in their lives. I'm speaking from experience people, so don't get all upset with me. There's no way things are going right for you if you're driving for Lyft or Uber.
That kid is truly terrified. I hope this guy made the kid feel better. It's not like it's his professional responsibility, and obviously the mom doesn't really care about his well being, but still. He could be the kid's new dad for real. He doesn't need to have a relationship with the mom. He can just be in the son's life. That could be special.