Let’s go gentle here, before anyone gets high blood pressure.
When a bishop grants an Nihil Obstat, he is simply saying that there is nothing in the writing that is contrary to doctrine.
He is not saying that he agrees with the content.
In this case, it is true that there is a Protoevangelium of James. It is true that the Protoevangelium says these things. It is also true that none of this is contrary to dogma. The dogma is that Mary, not Joseph, was a perpetual virgin.
Personally, I don’t believe the widower story. I think it’s mythology. But that’s me. We know very little about St. Joseph to say much one way or the other. All indicators are that “brethren” or “brothers” is more inclusive than just siblings. If you read the call of Abram, it tells you that Abram took his brother’s son Lot with him. It does not say “his nephew”.
We are left to guess whether Lot is a nephew or the son of a relative. If we go forward in John’s Gospel, it speaks of there being a Mary at the foot of the cross who was “His mother’s sister”. This is kind of the same thing. It is very unlikely that this would be Jesus’ aunt. Jews have a very strict tradition. They do not name children after a living relative in the direct line. In other words, I can’t be named after my grandfather unless he’s dead. I can be named after a cousin. Were the two Marys sisters? Probably not. Were they relatives? Yes.
Even Elizabeth’s relationship with Mary is questionable. The word cousin was inserted later. Originally, it said “kinswoman”. Obviously a relative, but what degree is unknown. It is pretty obvious that Jesus and John did not know each other. It is more than likely that the two households were not very intimate with each other. In other words, he and John, even though they were the same age, were not the cousins who played together and attended Hebrew school at the same synagogue.
There is much guess work on the word “brethren”. There is also much historical analysis that still has to be done on the protoevangelium. But it is a fact that the part quoted in the article is not contrary to the dogma of the perpetual virginity of Mary or any other dogma.
There is no dogma about Joseph’s virginity.