Problems with D'Antraigues Claims to Have Seen Precious Manuscripts at St Macarius Monastery

Let's count the problems with this story that Osborn picks up about a visit to the Coptic monastery of St Macarius by a French noble and his witness of several rare manuscripts including Clement's Hypotyposeis:

1. It is unusual to say the least, that you would find Greek manuscripts of this sort at a Coptic monastery.
2. No one else who visited the monasteries saw these texts.
3. D'Antraigues has a pronounced tendency to exaggerate.
4. He tends to 'run into' texts he happens to be interested in - i.e. ancient historical texts. 
5. Every important visit on his trip has problems when you dig into the details.
6. D'Antraigues offers up dating of the manuscripts which he could not possibly have the necessary expertise to ascertain.

With that said, the claim to have seen the Hypotyposeis of Clement isn't entirely typical of this trend.  D'Antraigues took an interest in Livy in his writings and claimed to have been offered an Arabic text of Livy at St Catherine's.  D'Antraigues wrote a satirical work developed from Polybius and claimed to have ran into a complete text of Polybius at Macarius.  So at least part of his claims are suspicious.  But D'Antraigues took no interest in Clement or the Church Fathers.  He seems entirely indifferent to Christianity. 

Is it enough to suppose that he made up the whole account of seeing rare manuscripts at Macarius?  Perhaps.  It would seem prudent not to lay too much significance to his claims.  Nevertheless there is a part of me that wonders whether the addition of historical texts is the exaggeration and there is some shred of authenticity to the claim to have seen something related to the Hypotyposeis at Macarius.  How far do we go with this?  Do we doubt that D'Antraigues even visited Macarius?  It is a truly fascinating problem the deeper you dig.