I meant the issue of causing and taking offence.
For me it hangs on whether offence was intended.
But that's impossible to measure. And it shifts the burden of proof onto the victim. I like the analogy with stepping on someone else's toes
: I may not have intended to cause pain, but I have done so; the victim's pain is real and does not require justification; and it's not unreasonable that I should acknowledge my mistake, and the pain I have caused, with an apology. If I do not apologise, well, I come across as a bit of a cunt.
Moreover, as Andy points out, we live in postmodern times, and today's archetypal racist uncle knows how to blur his racist banter with layers of irony. This is the defence that privileged people love to use: I have convinced myself I'm not a racist, therefore if a person of colour has taken offence at something I've said, it's because they're too touchy, or don't have a sense of humour, or are deliberately looking for racism in whatever I say. Personally, I have more faith in black people being able to spot racism than white people, since one of the main benefits of white privilege is to be blind to the myriad ways in which white supremacy pervades our culture. And since I'm not very good at identifying racism, I will certainly be guilty of it — even though I do not condone it. When that happens, it's up to me to say sorry, and to learn from my mistake.