Proper Etiquette?

I had a rental inspection later today by the city of Richfield, so I was in the renter's side of the duplex with the inspector while he did his walk through looking for infractions. We passed easily, so Ming and his "you're a slum lord" can just bite me. But the inspection brought up a particular question: What is the proper etiquette surrounding if their directional prayer hanging is actually pointing them at Duluth for their daily prayers? Be secretly amused that they're worshiping a lift bridge? Tell them? I went with keeping mum...I'd probably get in trouble for some sort of religious persecution as a landlord for mentioning it.