Hi Kindra :)
I understand what you are saying here, that you changed your mind because you came to realize his logic was correct and your logic was flawed. This is of course the best reason you changed your mind. But I can’t see this as a loophole, like you said. You did in fact have a significant emotional event. In your case the emotion was anger. Which laid the groundwork for your mind to get changed.
What I meant to say, had you not have this emotional response to his words; had you shrugged it off indifferently and moved on with your life, you would still have your original mindset. It was logic working together with your emotions that made your change.
I think sometimes people get into fights (people who are not plain assholes in daily life at least) because getting people good and angry does gets results. Even if it’s not the desired result, it will get a result.