Ah, an interesting topic.
Joly was a freemason and a friend of Adolphe Cremieux of the
Alliance Israelite Universelle.
There are a few similarities between his dialogue and the Permanent Instruction of the Alta Vendita.
For example the use of the phrase "the hundred arms of Briareus."
Finally, there is the fact that Joly's work seems to heavily resemble Eugene Sue's works. Eugene Sue was also a freemason, who fled France when Napoleon III came to power, a godson of Empress Joesphine.
His work targets the Jesuits, but perhaps the reality is that it was drawn from a source from inside ʝʊdɛօ-masonry?
An explanation for the resemblance of the Protocols and the Joly Dialogue is that there is an authentic common source from which material was drawn for both.
Finally, it's important to remember that belief in Jєωιѕн conspiracy did not start with the protocols, and is not fundamentally based on the authenticity of the Protocols. That is a myth.
Here's a good example of a text from 1890s Cincinnati:
http://www.biblestudysite.com/reddragon.htmIf the Protocols are authentic, certainly there is a Jєωιѕн conspiracy. However, if they are not authentic, it does not at disprove a Jєωιѕн conspiracy.