Exactly..People just don't get what you're saying. Imagine something comes your way at an instant, even if it's aimed at your foot. The moment you move your foot out of the way means that you were able to dodge it.
+rep
And Kabuto also said in that page that the best attack can become the best defense, MEANING THE AMATERASU WAS MEANT AS AN ATTACK FIRST BUT USED DEFENSIVELY LATER.