The final battle was just won and not bye who you may think. See when it was Harry's fourth year at Hogwarts during the last task when Voldimort was brought back, they both realized that memories had been repressed and strived to get them back but when they did they were shocked.
"Harry how could you turn your back on us? On the wizarding world in general?" asked Albus. "because you all tried to keep me from my real father. As far as I'm concerned you all can go rot." replied Harry.