More details- are we talking fish or shrimp? It's hard to find US shrimp on the menu in a lot of places these days, and I wouldn't hold that against a restaurant. As for fish...There is nothing on their menu that is identified as Vietnamese catfish. If you're convinced they're substituting fish, file a complaint with the Department of Agriculture and Consumer Services.
The story just sounds odd to me because in every case of fish substitution I've heard about in these parts, both the invoices and boxes do not identify an Asian point of origin- it's mislabeled that it's domestic.
I crossed paths with Dewey on a work project a few years back, and I like him because he's one of the few people in Destin politics that seems to have both head and heart in the right place, and I don't like to see him accused of something like that.