"If you are referring to the Protoevangelion of James that contains some of the stories of the early life of the Theotokos, etc, these are most emphatically *not* infallible writings.
These writings, I am pretty sure, came out of heretical sects.
Yes, that's the one I'm referring to."
I have read that the Protoevangelium is from a heretical even Gnostic source, but I have never read that The Church took that position. The Fathers quoted quite liberally from it and of course in Orthodoxy, we have several feasts commemorating events spoken of in it as well as the names of Panagia's parents. As Agrarian says, it isn't scripture as such nor is it per se an "infallible document", of course neither are any given writing of any given Father so far as Orthodoxy is concerned, but it is certainly part of the Holy Tradition which the Fathers drew upon.
Then perhaps the technical definition of Holy Tradition is slightly different for Catholics and Orthodox. I just pinged you both to another post on this a little while ago. Maybe we can figure it out there.