RE: I think the author is confusing the doctine of "one substance" from Nicea with the filioque.
I think you are correct.
I cited this article to highlight the political power struggles that were occurring during the development of the Nicene Creed. Avenger had posted that "the bible was compiled by humans (politicians and religious leaders) 100's of years after Jesus." I agreed with him and used the article to support that. If you do a google search, there are numerous other articles that provide information on the politics behind the creed.
Given that creeds are human devices and subject to human error, many things such as politics and other contemporary issues will come into play. Their truth is only as good as how faithfully they model what is in the Bible.