Do you think that a 2 year 8 month sentence for a schoolboy throwing a fire extinguisher is right?

The incident occurred during one of the recent student protests when a fire extinguisher was thrown into an open space from a rooftop by a 6th form schoolboy who had no previous convictions.In comparison a mature adult police officer with a previous history of using violence against members of the Public aulted a member of the Public with a steel baton at a G20 protest.The member of the Public then died at the scene.Consequently the police officer may or may not be dismissed.Are the scales of justice now obsolete?