Did the scribes copy the letters correctly?

[Jorge_Stolfi]

The manuscript is a copy.

With that I agree.  The alternative is the "Brain to Vellum" theory -- that whoever composed the text wrote his message directly on the physical artifact kept at Beinecke.   But a copy of what?

The Scribe was not hired, he was working for himself

That is possible.  People often borrowed books that they wanted and copied them themselves.

The original was in a language barely known to the Scribe

I agree with that too.  So far, while our scenarios are different, they lead to the same situation.

I can easily imagine a person who owns some book that he can't read but for some reason believes that this book is of extreme value and thus must be copied at all costs.

Yes, that happened many times.  John Dee was obsessed with a Book of Sogya that contained nothing but some large grid tables filled with letters in mysterious patterns.  AFAIK no one knows how he got it, but if he saw it in someone else's library and the owner did not want to sell it, he surely would have borrowed it and had it copied.

I did that myself twice.  Once I copied by hand half a page of a biography of Jacobus in Latin (which I cannot read), in a library that did not allow xeroxing or photographing.  

And over the last year I digitally transcribed by hand 20 pages of a mysterious manuscript of unknown contents, written in a unique indecipherable script, which you may have heard about...

so the Scribe had to invent his own way to write down and even to read the glyphs.

This I find questionable.  If the text was written with isolated characters -- like Hebrew, Armenian, Cyrillic, Chinese, etc. -- the person would have to learn to distinguish the various glyphs of that alphabet anyway. Then he should just copy those characters as they were.  Inventing a different original alphabet would not help.  It would only slow down the copying, and the result would not be any easier to read.

And if the script was cursive, like Arabic, I don't see how he could have even started to do that.

Therefore, I agree that then VMS was copied by a Scribe who could not read it.  But he must have copied from a text in the same script.  

It could even be that someone has mistaken right-to-left script as left-to-right and wrote a "copy" of it in such a way.

I agree that it is possible.  The shape of the paragraphs and other details strongly indicate that the Scribe wrote it from left to right.  But he could have copied from an original written right to left, reading it left to right.  Maybe the line breaks are his own, or maybe he reproduced the original breaks too.

That is, the original may have been

  word06 word05 word04 word03 word02 word01 
  word12 word11 word10 word09 word08 word07
                              word14 word13

written right-to-left, and our Scribe may have copied left-to-right as

  word06 word05 word04 word03 word02 word01
  word12 word11 word10 word09 word08 word07
  word14 word13

or even as 

  word06 word05 word04 word03 
  word02 word01 word12 word11 
  word10 word09 word08 word07
  word14 word13

Either possibility would have embarrassing consequences for anyone who has been analyzing correlations across word and line breaks...

Unfortunately, such a theory is very hard both to prove and to disprove.

I don't believe this last part (right-to-left original) is true.  But, if it were, one might find evidence of it, even without deciphering the text.  Just as we find evidence that the Scribe wrote left-to-right, and did not understand the text, and wrote Aries in the Zodiac before Pisces, and both before the Bio section...

All the best, --stolfi