Ceebeegeebies, well IMO that's just plain daft. All kids need an emergency contact number, they cannot be expected to navigate the world without being able to call for backup. No matter who you are, stuff happens.
I am reminded of the time Euan Blair was found in the gutter after his GCSEs, when they had to take him into custody. Apparently the call was interpreted as Chief of Police Ian Blair being found in the gutter as it was misheard ... anyway, his mum was in Portugal at the time and Tony Blair appeared to have no idea where his son had got to, and none of Euan's friends had the decency to stick him in a taxi and point him in the direction of Downing Street ... perhaps that's what you face when you're the child of the PM.