Has anyone else read the beginning of the Prima strategy guide for this game that states that this game is based on real life events and characters, and even uses the real names? The guide says an Infogrames employee visited cousins in Louisiana and discovered Derceto and it's story during that visit. Why would they have lied like that?

Do you happen to be able to scan the page with those things mentioned or just copy the text verbatim?

Sounds like something Lovecraft himself could have done. He often wrote in a style that imitates scientific reports and apparently there's people for whom the Necronomicon is for realz: http://www.abovetopsecret.com/forum/thread462175/pg1

Maybe they thought it wasn't plausible enough to actually gull anyone and so they could use the fiction author staple without persecution.

It's not true.

It's rather common thing in horror or fantasy literature to claim that some fictional story is true and that the narrator or the writer claims that they experienced the whole thing themselves or learned the details from somewhere. One of the most famous examples is Edgar Rice Burroughs, who claims that John Carter of Mars is his uncle and told his adventures to him personally.

Like previous poster said. Lovecraft's protagonists often claimed that their stories were true and I assume that the guy who wrote the strategy guide wanted to imitate that.

Lovecraft also included real life discoveries that occurred at the same time he was writing to add more weight to his work. For instance, he mentions the discovery of pluto in the story "Whisperer in the darkness".