CathInfo.com

Yes, I agree it would take an extreme failure in education to fail in the way you are thinking of. In practice, some other issues would likely appear well before a priest were to "fail this way" specifically.

A failure of education this extreme should have prevented a man from entering the seminary in the first place, assuming that this actually is a resistance priest.  

This alleged priest took a quote from a section clearly and repeatedly identified as containing false opinions of others and left out the beginning of the sentence which said "they make a further argument, namely that..."  Instead, he presents this argument for flat earth as the position of Aristotle/ St. Thomas, introducing it with: "After all these commentaries, he concluded that to be stable, the earth must be flat."

This alleged priest also claims that St. Thomas does not say that Aristotle's opinion is right, in spite of the multiple instances of St. Thomas referring to Aristotle's views on the position, rest, and shape of the earth as the truth. For example, at 480, when St. Thomas outlines Aristotle's argument he says: First he pursues the above-mentioned three things [position, rest, shape] according to the opinion of others; Secondly, according to truth."
 
To make errors this serious, a person would have had to fail in basic skills of reading comprehension that he should have learned in high school.  I'm not sure about the SSPX, but other seminaries I know of accept entrants who have post-secondary education.  But even a high school graduate should have been able to understand from this docuмent that neither Aristotle nor St. Thomas thought the earth was flat.

If this article was actually written by a resistance priest, I suspect this could have negative repercussions for the resistance.  This seems like something that could seriously undermine their credibility.  And it draws attention to a possible weakness of the resistance.  It lacks the authority structure that ought to exist in the Church.  When a priest goes off the rails like this, there needs to a bishop over him to correct him.  I am not sure this can happen in the resistance.

I have little knowledge, however, of resistance politics and dynamics.  I would like to hear from others on this aspect.

You should be careful before attacking priests like this. A little bit of respect won't go too far astray.

If I see any evidence that this article was actually written by a priest, then I will apologize to him.  I intend no disrespect to a priest.