AITA for saying that no one is ever 100% right?

My guy friend (FWB) has a really fragile (intellectual) ego. I’m 22 and he’s 35, for context and I’ve known him for many years. For instance, we were talking about something and he joked saying “have I ever been wrong?” and I said “that’s debatable 😂 “. He got so upset with me asking about specific times and (exact) wording that he’s said. He said that I am calling him liar because he actually said that he’s not wrong about things in general.

I feel as if he thinks I’m challenging his intelligence when that was never my intention. It was a joke on my end as a way of basically saying no one is ever 100% right, and they aren’t. Despite me telling him that it was meant as a joke - which it was hence the laugh emoji - I also said this to calm him down. I told him to let it go since it’s not that serious and wasn’t meant to be deeply looked into. He keeps going at it trying to remain provoked. This is just one example. Anything we have ever argued about, it’s because he’s trying to prove his point is right, not taking logic into consideration. Even if I let him “win” since I try to remain peaceable, it’s never sufficient for him. It’s emotionally draining when you want to move on and someone wants to stay on the topic of argument. I feel like he has nothing to prove to me. AITA for telling him that no one is ever 100% right?