You are right. I would not expect most people to do what this man has done, but I do wish that he had simply refused the job without explanation. Trying to justify one’s actions, even when they are justifiable, often leads to more trouble than otherwise.
When they passed no smoking in bars and restaurants in Ohio, many commentators suggested that a club that one had to join was the legal way around the dilemma. Many bar owners considered it. I don’t know what the final breakout was. What it boiled down to was your joining a club and the sign-up included agreeing to a set of principles, standards, and non-accountability statements. Then you were able to gain entry and smoke and drink. The bar was no longer liable, since each club member had agreed to their set of principles.
In American business, we have Sam’s Club that also has a sign-up.
I envision this same format for bakers, florists, etc. A baker could be a simple bakery, but customers who wished could sign up for a “wedding club” or “special events club” that was advertised by the bakery. Without being a member of that club who had agreed to principles and non-liability statements, there would be no wedding cakes that were ever produced by that bakery. Those decorations would always be from a separate entity....a club that one could choose to join or not join.