It’s more likely it’s his right not to take a gig in a restaurant environment, where, of course, they’ll be selling meat. But to demand that the venue limit their opportunities to make money is wrong. Just as the Christian band shouldn’t take a gig at the venue if beer being sold bothers them. But to take a gig and make demands what the venue can and can’t sell is just wrong.
Is that what happened? I took it to be that he needed those demands met to take the gig. I could be wrong though.