...I could easily see that happening. I know all too well how what it's like not to save. Fortunately, since you entered the necromancer's house and left, there should be an auto save of you leaving it right? I'm kind of surprised that necromancer hunted you down.
Actually, that one dragon is the final boss of the game I think so it's not just a dragon, it's THE dragon of ALL dragons. I actually hope that he's significantly stronger than the other enemies though.