I keep thinking about discourse. And people tend to get "harumph harumph" when apologies aren't "sincere enough". There's some cases where that may be an understandable reaction, but at the same time, who are you to say an apology isn't genuine? You don't know these people.
What's more important to me is if they apologize, it's clear in their actions they've learned from it. If the person in question doesn't repeat the same mistakes and appears more contentious, then I think they learned their lesson. Actions speak louder than words, yk?