geoffreycaveney's Judaeo-Greek theory

[ReneZ]

If the source text of the Voynich MS *really* was written in an unpointed Hebrew version of Greek, then there are two possibilities:
1) the person converting it to Voynichese did understand which vowel should be where
2) this person did not understand.

Now the Voynichese text (according to this theory) has vowels, in the right places, but not the right ones.
This does not fit with either option.

It depends how you define "the right ones". As I have already pointed out previously, in Judaeo-Greek the Hebrew letters Aleph and Ayin have identical phonetic values:

[ there was a figure here that did not survive my copying ]

Thus, if Voynich [a] represented Aleph, and Voynich [o] represented Ayin, the author could have used either of them, interchangeably, in any place where either of them could be written in Judaeo-Greek, in free variation, without having any effect on the pronunciation of the underlying text.

But this is not at all what you are doing. I just went to the first example of a translation that I could find:

first two lines of You are not allowed to view links. Register or Login to view. 1 in the Voynich ms text:

[t]eeodaiin  shey  epairody  osaiin  yteeoey  shey  epaiin  oaiin
daiir  okeody  qoekeeg  sar  oeteody  oteey  keey  key  keeodal

my Judaeo-Greek interpretation of this text:

[]ei[A]pan  tis  ipeirous  otan  skiiAis  tis  ,  epan  oAn
par'  Atous  &Atees  tAr(a)  oikous  o(u)k-eis(i)  tees  ,  tes  []ei[A]pan

Now "normalizing" this Judaeo-Greek text into a more standard Greek form:

eipan  tis  ipeirous  otan  skiais  tis  ,  eipan  oun
para  autous  &  autes  tora  oikous  ouk  eisi  tes  ,  tes  eipan

So starting with the Greek text, we have lots and lots of vowels.
In the Judaeo-Greek version, they all survive somehow. That does not fit with an unpointed Hebrew text.
Just some examples (to keep it simple):

tis should have become ts.
para should have become pr.
tora should have become tr.
tes should have become ts.
[ etc ]

eipan could have become Apn (with A the Aleph). There are three of them in this short text.
But two end up as: eiApan
and the third as: epan

and finally in Voynichese they are all different:
[t]eeodaiin
epaiin
keeodal