The Dilemma of Josephus Flavius

The historian Josephus Flavius is controversial to this day because of one event that occurred when he was the commander of the Galilee in the Great Revolt against Rome. When the city of Yodfat fell to Vespasian, Josephus turned himself over to the Romans to save his life. Was this a legitimate act of survival, or was abandoning the campaign a betrayal of his people and his comrades in arms?