Guidelines on treatment of members of family of medical practitioner — Doctor treating her own son — autistic child — appropriate medication — practitioner’s observance of guidelines as to treatment of members of own family — attitude to complainants — practitioner’s attitude to professional assessment and criticism — defamation proceedings commenced against professional medical witness during proceedings — defamation process served on witness two days ahead of that witness giving evidence — Interpretation of Health Practitioner Regulation National Law as purposive legislation — absence of evidence sufficient for reinstatement — costs on re-registration application.