We must remember that someone's bad day or slip of the tongue is probably multiplying tenfold for those regularly on the receiving end of discriminatory language.
I only suffer discriminatory language on a small scale, compared to what many other members of the community endure. Sometimes when I receive a curious question or a nasty remark about my skin or appearance from a stranger, someone I know will come to the stranger's defence, saying "they probably didn't mean it, maybe they've had a bad day?" So maybe 10 people today have had a bad day? And in my opinion - based on the experience of being on the receiving end of curious and nasty, and sometimes, discriminatory language - a bad day is never an acceptable excuse for discriminatory language or behaviour.
Nor is any other excuse.
It's not acceptable to say "It's ok, I can say that, my brother in law is black."
It's not acceptable to say "But look at the evolution of language! Those derogatory words have different meanings."
It's not acceptable to say "You're not disabled like those disabled people."
It's not acceptable to demean a nation's leader because you don't like their policy.
It's not acceptable to say "But you're different. We don't see you as Asian."
It's not acceptable to say "I've got a friend who's gay. He doesn't mind me saying 'faggot'. (He probably doesn't feel comfortable speaking up if that's your attitude.)
It's not acceptable to say "But I haven't been taught non discriminatory language."
It's not acceptable to say: "I didn't mean it like that", or "It was a slip of the tongue."
It's not acceptable to say "It was just a joke. An in-joke. Can't I have a laugh?"
It's not acceptable to say: "Harden up, mate. I didn't find it offensive."
There's no need to pity someone for identifying as part of a minority group. The only pity they need is for being on the receiving end of attitudes like yours.
It doesn't matter that the person you're joking about or criticising may not hear it. Somebody will hear it, and somebody will say "that's offensive."
Whether you're a private nobody, or a football club president and radio presenter, or a member of a political party, or the owner of a restaurant, or a parent teaching your child how to behave, discriminatory language is not acceptable.
Disclaimer: References to Eddie McGuire's 'slip of the tongue' and Kevin Rudd and Prime Minister Julia Gillard on the menu do not reflect my personal or professional opinion. Picture of dialogue between Eddie McGuire and Luke Darcy taken from The Shake. Picture of that menu sourced from Paul Murray's Twitter account.