@Jyq I think the issue is that you're looking at the situation through a modern perspective, while the story is built around very different values.
This is a knightly setting, where honor, pride, and keeping one's word are considered extremely important, sometimes even more important than life itself. Because of that, the apology isn't just a simple "sorry"—it's an acknowledgment of wrongdoing and a matter of honor.
From that perspective, his reaction makes a lot more sense. In a modern setting or something like post-apo story, I would agree that the response seems unnecessary. But in a world built around chivalry and knightly ideals, refusing to apologize after causing such an offense can be seen as a very serious act.
That's why I think the context of the story and the duel matters here. The characters aren't acting according to modern values; they're acting according to the values of their world.
Feel free to dislike my comment or review – that’s your right! But at least I'm making an effort. If you can't handle different opinions, you might want to rethink being on the internet. Stay safe!