I think that when an apology is not promptly offered, especially for an egregious mistake, it's very telling. People know when they fuck up or do something wrong. (Certainly in more extreme situations at least.) And when it's not offered, the relationship should suffer because clearly the one person isn't willing to acknowledge they did something wrong for whatever reason - because they're a coward or because they're too proud. (Ironic how it's both sides of the spectrum.) If I don't agree with someone who is raising something I've done to make them upset I will tell them I am sorry they feel that way. I do apologize. I just only apologize for what I feel is merited. At that point I have acknowledged the other person's ruffled feathers and it's about "where do we go from here," if it's a person I even want to have that conversation with. There are truth be told a few people (2) who I would not even say "I am sorry you feel that way" to. But they are people who I no longer care about how my actions make them feel
by the way, I hate hearing, "I'm sorry you feel that way." It seems like a complete rejection of my feelings and not an apology at all. Maybe "It sounds like not making it to the Star Wars movie really upset you. It upset me too. I wish I hadn't been sick and I could have followed through with my suggestion to go. Is there anything I can do to make it up to you?"
It really is, that to me is a red flag on anyone... whether romantic, friendly, professional, acquaintance.... and the "where do we go from here" conversation is one that works only if both people are willing to let go of any negative feelings they had about a situation and heal things. Mutual humility is favorable in the pursuit of resolution and concord between contentious parties. Going beyond just recognizing someone's ruffled feathers, discerning how our own actions were unskillful in that they put as odds with another: If we can discern that, then apologizing becomes genuine, and we benefit as well as the other. We apologize healing each of us benefitting us in the now and then seeing how our actions were the cause of previous conflict, we can abandon those actions so it doesn't happen again–that benefits ourselves in the longterm. Of course in the case where we did have good discernment and saw that our actions were not the cause of someone's contentiousness, then there is nothing we can do.I think that when an apology is not promptly offered, especially for an egregious mistake, it's very telling.
At that point I have acknowledged the other person's ruffled feathers and it's about "where do we go from here," if it's a person I even want to have that conversation with.