> My view is that if you offend someone, however innocently and unintentionally, it is good manners to apologise.
That's only true if, with the benefit of hindsight, you can see how they could reasonably have taken offence.
In this instance that's not true. If he felt the need to explain himself at all, what Matt Taylor could have said was "It was a special day so I wore my favourite shirt, one a good friend made for me." And that should have been an end to it - no apology necessary, nor even any further explanation (e.g. the friend was a woman, it was a birthday gift, she is a fetish model, etc.)
What the shirt depicts is women wearing clothes that they have chosen to wear. Most feminists would argue for women's rights to do that. So why would they have an issue with a man wearing a shirt depicting women doing exactly that, made for him not in some sweatshop but by a friend?
As for an apology ... maybe "I'm sorry you're such a sanctimonious fool."