Article 4 (Superior Orders)
If any person who is under legal obligation to obey orders of the Government or the superior commits genocide or other crimes against humanity without knowing that the order was unlawful and have justifiable reason for not knowing this, he or she shall not be punished.
Orders to commit crimes of Article 8 or Article 9 are manifestly unlawful in case of paragraph (1).
Superior orders - national proceedings
EDIT.