According to custom, it is permissible for a belligerent warship to use false colours and to disguise her outward appearance in other ways in order to deceive an enemy, provided that prior to going into action the warship shows her true colours. Aircraft are not, however, enentitled to use false markings.
In land warfare, such operations are generally deemed acceptable under certain circumstances, such as to deceive enemies, provided the deception is not perfidious and that all such deceptions are discarded before opening fire upon the enemy. Similarly, in naval warfare such a deception is considered permissible, provided the false flag is lowered and the true flag raised before engaging in battle.
Sokka a member of the water nation defended against an attack by the fire nation. During such defense, Sokka was in a hot air balloon that had the fire nation insignia. Sokka did not change to water nation flag or anything before counter-attacking.
Did Sokka commit the war crime of false flag, assuming our laws applied? Or did Sokka commit some other war crime for such actions?