Headscratchers / Indiana Jones and the Fate of Atlantis
In the Lost Dialogue, Hermocrates says that Critias mistranslated Egyptian into Greek and gave a tenfold error when citing the distance of Atlantis from Greece and the era in which it existed. Socrates then comments that the actual numbers must be a tenfold fewer, since a tenfold greater is ridiculously over the top. So why do Indy and all the other characters refer to it as "Plato's tenfold numbering error"? The error is Critias's. Plato simply wrote about it in his dialogues. For that matter, how silly is it that Hermocrates knows Egyptian numbering well enough to realize that Critias was wrong by a factor of ten, but not know whether it's a multiplication of ten or a division of ten? He basically says, "I know you're wrong Critias, but I don't know HOW you're wrong."
It could either be because it is Plato's book, or because Plato does not bother to correct Critias, so Plato is also wrong.
I think the nature of written ancient Greek philosophical dialogues should be noted here. They were not transcripts of conversations that actually happened, but a literary device for the writer to explore philosophical issues and promote their views. Ultimately what is said in the dialogue should be attributed to Plato, regardless of who is credited as saying it within the dialogue.
What is Plato's lost dialogue doing laying around a college somewhere, much less an American college?
It was in a collection of historical documents that were left to the college, probably in somebody's will. Nobody had gone through it and catalogued them all yet. That's not at all uncommon. It's slow work that can only be done by an expert. Do a Google search for "lost manuscript found" - things are turning up all the time as universities and libraries slowly work through their stuff.
So if the numbers should all be a tenfold fewer, why on earth do they multiply the number of orichalcum beads by ten in the last scene? Once they've established that the tenfold-fewer value doesn't work, wouldn't trying the actual value listed in the dialogue be next?