Eventually they’ll just come out and take it down for him.
I know of a situation locally where a business went ahead and stared building without permits. When stopped by someone who noticed what they were doing, the town just whined that he started building and they couldn’t make him take it apart, so they gave him the permit. Well, yes they could make him take it apart. He was working on the forgiveness is easier than permission angle.
If this guy’s board is the bunch of wusses this other town board is, he’ll be fine.
He just has to know how to play them right.
Besides, it’s private property.