Is someone wrongfully killed while defending his children considered a martyr, as ruled by one of the muftis on Algerian Terrestrial Channel, or is he in Hellfire, as stated in the hadith: "The killer and the killed are in the Hellfire"?

The Hadith (definition): "When two Muslims meet with their swords, the killer and the killed are in the Hellfire," is authentic. The meaning of the killed being in the Hellfire is that he was eager to kill his companion. And whoever dies in defense of his property, or his religion, or his life, or his family, is a martyr, for the Prophet, peace and blessings be upon him, said: "He who is killed defending his property is a martyr; he who is killed defending his religion is a martyr; he who is killed defending his life is a martyr; and he who is killed defending his family is a martyr."