The title or deed - whatever its called in NC - will list all covenants and restrictions on the property. If it says no veggies then he will have to destroy his garden. The "architectural and landscaping standards" don't mean doo-doo unless the legal documents tie the property to those standards. Another way to get around them is to read everything associated with the covenants and restrictions and see if the HOA¹ has been conforming to the legal requirements.
In my experience the local judges and lawyers are financially tied to the local real estate agents. Stan can try and sue but he'll lose unless his connections are better than the HOA and local real estate people.
¹ HOA = Home Owners Association. In every case I know the committee members are bottom feeders. A doo run-run-run, a doo run-run
