"Yes. In the end." It was oversimplification again. But also truth. "There was a final battle, at Hogwarts. It ended in a duel between them and the war ended when Voldemort died by his own curse, rebounding off of Harry's."
Neville didn't mention his own or Snape's involvement either way. This man hadn't done those things yet and, as much as Snape himself would probably call Neville foolish for thinking it, Neville wanted to believe that even he could change without the weight of Voldemort on his shoulders.