Acknowledging the mistake immediately seems like a good start, as I've said.

Life doesn't always have to be from the perspective from “a manager”, these are community volunteers doing untold hours of unpaid work. Just be a person, whose acquaintance is upset you replaced their handmade postcard with an AI-generated one.

Acknowledging a mistake, no matter genuinely or not, doesn't solve the situation. It just makes victim feel good a bit.

Agree on manager view, I was rather putting situation in a wrong perspective. It doesn't change the questions though - what would you do to resolve the situation (not to make the other side feel good)?