Why Was Billy Bunter Never Really Expelled?

After the success of How Did Long John Silver Lose His Leg?, Dennis Butts and Peter Hunt take their forensic lenses to more mysteries that have troubled readers of children's books over the centuries. Their questions range from the historical to the philosophical, some of which are puzzling, some of which are controversial: Why does it seem there are no Nursery Rhymes before 1744? Why did God star...