Here's Keith's Victoria Cross citation:
On 24 May 1969, in Kontum Province, Warrant Officer Payne was commanding 212th Company of 1st Mobile Strike Force Battalion when the Battalion was attacked by a North Vietnamese force of superior strength.
The enemy isolated the two leading companies, one of which was Warrant Officer Payne's, and with heavy mortar and rocket support assaulted their position from three directions simultaneously. Under this heavy attack, the indigenous soldiers began to fall back. Directly exposing himself to the enemy's fire, Warrant Officer Payne, through his own efforts, temporarily held off the assaults by alternatively firing his weapon and running from position to position collecting grenades and throwing them at the assaulting enemy. While doing this, he was wounded in the hands and arms.
Despite his outstanding efforts, the indigenous soldiers gave way under the enemy's increased pressure and the Battalion Commander, together with several advisors and a few soldiers, withdrew. Paying no attention to his wounds and under extremely heavy enemy fire, Warrant Officer Payne covered this withdrawal by again throwing grenades and firing his own weapon at the enemy who were attempting to follow up.
Still under fire, he then ran across exposed ground to head off his own troops who were withdrawing in disorder. He successfully stopped them and organised the remnants of his and the second company into a temporary defensive perimeter by nightfall. Having achieved this, Warrant Officer Payne of his own accord and at great personal risk, moved out of the perimeter into the darkness alone in an attempt to find the wounded and other indigenous soldiers. Some had been left on the position and others were scattered in the area.
Although the enemy were still occupying the previous position, Warrant Officer Payne, with complete disregard for his own life, crawled back on to it and extricated several wounded soldiers. He then continued to search the area, in which the enemy were also moving and firing, for some three hours. He finally collected forty lost soldiers, some of whom had been wounded, and returned with this group to the temporary defensive perimeter he had left, only to find that the remainder of the battalion had moved back. Undeterred by this setback and personally assisting a seriously wounded American adviser, he led the group through the enemy to the safety of his battalion base.
His sustained and heroic personal efforts in this action were outstanding and undoubtedly saved the lives of a large number of his indigenous soldiers and several of his fellow advisors. Warrant Officer Payne's repeated acts of exceptional personal bravery and unselfish conduct in this operation were an inspiration to all Vietnamese, United States and Australian soldiers who served with him. His conspicuous gallantry was in the highest traditions of the Australian Army.