How people feel depends on their own assumptions on why you made the mistake. Say that yours was a perfectly natural mistake based on innate heuristics, and there is no value judgement implied. If this is the way your mistake is interpreted, no feelings are hurt. But if you spread the idea that this is racism and a value judgement is implied, then feelings are hurt, and it becomes a serious issue.
So the way you frame the issue actually ends up creating the issue.