Agree with MOR entirely here. This was a tragic accident with no intent whatsoever. The pilot involved, if he is a normal human being, will spend the rest of his life reliving the incident and suffering the guilt involved. The parent may feel his daughter's life deserves a pound of flesh, and I can understand that some would think that way.
Though it's purely hypothetical I like to think that had a daughter of mine been the victim, after the initial shock I would accept it as an accident and realise nothing would be gained by destroying another person's livelihood.
Maybe I wouldn't be so forgiving; who knows until it happens? But those sitting comfortably in their homes demanding this young man come back to "face up to his actions like a man" should put their self-righteousness aside for a moment and ask themselves what they would do in the same circumstances. Go on, have a long hard think about it and try to be honest. What would you really do? I don't want to hear your answer; it's for everybody to wonder for themselves.