Australian Timothy Weeks and fellow hostage American Kevin King were teachers at the American University of Afghanistan in the capital Kabul, when they were kidnapped near their university campus in August last year.
It is the first time the pair has been seen since their abduction.
The soldier fired more than 400 rounds, launched 17 grenades and detonated a mine to thwart the Taliban assault on his checkpoint near Babaji in Helmand Province, southern Afghanistan.
Despite the presence of more than 140,000 foreign troops, backed by 300,000 Afghan soldiers and police, the Taliban have managed to spread beyond their traditional strongholds in the south into formerly peaceful areas like Kunduz.
They spoke on the condition of anonymity because the government had not yet released figures.
An official in Washington had initially put the toll at more than 50 killed and wounded.
I would like to thank my nurses, doctors and the staff of the hospitals in Pakistan and the UK and the UAE government who have helped me to get better and recover my strength. Dear friends, on 9 October 2012, the Taliban shot me on the left side of my forehead. They thought that the bullets would silence us, but they failed. The terrorists thought they would change my aims and stop my ambitions. I want education for the sons and daughters of the Taliban and all the terrorists and extremists. Even if there was a gun in my hand and he was standing in front of me, I would not shoot him.
I fully support UN Secretary General Ban Ki-moon in his Global Education First Initiative and the work of UN Special Envoy for Global Education Gordon Brown and the respectful president of the UN General Assembly Vuk Jeremic. But nothing changed in my life except this: weakness, fear and hopelessness died. This is the compassion I have learned from Mohamed, the prophet of mercy, Jesus Christ and Lord Buddha.