The Gadianton army recognizes its defeat, and flees back to its homeland. Gidgiddoni orders that they be pursued. In a weakened state from battle, the Gadiantons would be fleeing for their lives, but in flight perhaps not as well organized as in the attack. Additionally, the nature of an attack against a fortification is that the attacker must use large numbers against the fewer that are required to hold the defensive line. It is quite possible that the army Gidgiddoni led had been part of the reserves of the Nephites, and were fresher for not having seen action on the walls. The end of the story comes with the death of the Gadianton general, Giddianhi. As Mormon tells the story, he appears to have some respect for the fighting prowess of Giddianhi has he notes that the general falls because of weariness, not lack of skill in fighting.
Even though this was the end of Giddianhi the robber, it was not the end of the Gadianton robbers. The strength of their position and population is indicated in their ability to quickly mount another offensive.