...and he didn't really "decode" them very convincingly. They might be abbreviations, ideograms, or just nonsense. One thing I'd take a little issue with: the debunking person in the piece you linked said that the resulting Latin was ungrammatical. That's true; but this could be a result of Gibbs' poor Latin. It doesn't prove these aren't abbreviations, or that some of the characters aren't. The most ungrammatical aspects are wrong case endings for nouns, e.g., showing the nominative form of a noun after a preposition requiring the dative or ablative. Clean that up, and this aspect of the debunking becomes sort of moot.