Found a better answer -- and one that contradicts wiki: Can I trust these source?
1.
. . . He was a postmillennialist who had been heavily influenced by the Reconstructionist movement. In fact, he was the (
unordained) pastor of a Reconstructionist church in Fairfax, Virginia.
. . . Hahn attended the theologically liberal but economically conservative Grove City College, a college affiliated with the mainline Presbyterian church, where he concentrated in theology, philosophy, and economics, and continued his activity in Young Life. While in college, Hahn “discovered that the covenant was really the key for unlocking the whole Bible” (17). Beware the man who thinks he has discovered some sort of “key” for understanding the Bible, whether it is the idea of covenant, a scheme of dispensations (instituted by covenants), or a five-point covenantal model.
. . . Although Hahn does not mention it in the book, his tuition at Gordon-Conwell was paid by a Calvinist Christian businessman who wanted to support a student who understood both free market economics and Christian theology, for the purpose of being able to teach economics to clergymen and Christian theology to economists. Hahn was highly recommended to the businessman by the Chairman of the Economics Department at Grove City. What Hahn learned at Grove City was Thomism, and his interest in economics - which he says he studied only to mollify his “practical” father, not because he was genuinely interested in the subject - has disappeared. Hahn’s obsession is to convert Christians to Catholicism, not to educate clergymen about principles of economics or economists about Christian theology. He owes one Christian businessman many thousand dollars and his former economics professor an apology.
. . . Hahn was also invited to teach at Dominion Theological Institute (which later merged with Chesapeake Theological Seminary).
. . . Hahn was also teaching his seminary students - contrary to what the seminary itself believed, contrary to what he was being paid to teach, and without informing the leadership of the seminary - that justification by faith alone was false. The fact that he was denying the Christian doctrine of justification while being paid to teach it does not seem to bother him. Oddly, Hahn opens his book with this story designed to illustrate his lifelong honesty:
“I recall the last time I ever attended our family’s church. The minister was preaching all about his doubts regarding the Virgin Birth of Jesus and his bodily Resurrection. I just stood up in the middle of his sermon and walked out. I remember thinking, I’m not sure what I believe, but at least I’m honest enough not to stand up and attack the things I’m supposed to teach”
(1). But that is exactly what Hahn did when he taught seminary classes, and that is exactly what he did when he accepted money for seminary tuition under false pretenses. After Hahn attacked sola fide in his seminary classes in Virginia, one of the students challenged him to defend sola scriptura. He could not (51-52).
After seven years in “Protestant” educational institutions, and now a Presbyterian minister, Hahn, who by all accounts was an excellent student, could not defend the major principles of the Protestant Reformation.
2.
". . . We reported that the Presbyterian Church of America (PCA) had no record of his ordination or any record of Trinity Presbyterian Church, the church where he had been a pastor. Mr. Hahn acknowledged these facts but offered an explanation.