I actually spent a couple years in a similar-sounding situation (and have similarly moved past the anger) so I unfortunately have a pretty good idea where you're coming from here. It's also a pretty different situation from what I think the discussion has mostly been centered around. I'm not sure how you handled the experience or what the general case is but I remember for me, for a while I was genuinely sorry for hurting them every time and then it eventually switched over to me just wanting to say whatever it took to stop the episode. It's actually a fair bit more complicated than that but basically the point of the apology wasn't really about remorse or making amends; for the other person it was about control and for me it was just a survival technique. I think it's a fair bit different from the general case, especially when public apologies are involved.
> Just because someone is offended doesn't mean they're right.
I don't think "right" is the way to put it at all. Even if we can say someone is or isn't right to be offended, I don't think it really matters. If you truly feel bad about somebody being offended, does whether or not you think they're "right" to be so really affect whether you feel bad about being a partial cause for that state? Or is it more that whether or not you deem them "right" really affects whether you feel bad about them being offended in the first place? That's not rhetorical; I'm genuinely curious but my expectation is that it's the latter. And note that for this I'm trying to differentiate between "feel bad about how they feel" and the sort of "feel bad about having to deal with this situation of them acting offended" I alluded to above.
I'm usually pretty good at empathy and understanding others' viewpoints but maybe some people are different enough from me in a way I'm having difficulty comprehending because I cannot imagine a situation where an action I take causes somebody to feel bad and where I genuinely feel bad about their feelings but I don't regret my role in causing that state. And I'm all too familiar with cases where somebody might have to apologise when they don't mean it but very, very few where they wouldn't benefit from trying to act sincere about it.