This interaction is the result of something I posted back in 2010 (and also here). Father Mitch Pacwa was gearing up for the October 2017 500th anniversary of Martin Luther’s posting of the 95 Theses. At the time, he was trying to put together a video series (as I now check his "Ignatius Productions" eight years later, it does not appear the project ever got off the ground). Back on March 08, 2010 he appeared on Catholic Answers live to discuss the Reformation. During the interview, a caller asked “In a nutshell, what did cause the Reformation?.” Father Pacwa answers, “Luther was racked with guilt.” What was this guilt from? Pacwa explains “he apparently had killed somebody in a duel.” To deal with the guilt of murder and “a legalism within his own personality” caused him to begin “looking at doctrine differently than it had been under the various Catholics prior.” This lead to justification by faith alone by grace alone.
Another Roman Catholic participant stated, "I’ll just say, stuff on the internet needs to be vetted carefully. People get labeled as saying things they don’t say or what they do say is so recontextualized it doesn’t come close to what was actually said," and also, "Swain [sic] was apparently pointing to the book that made the claim Luther was in a duel and killed his friend. The real question is, did Fr Pacwa really say what he is accused of saying?"
Well, Here is the mp3 clip to verify this is what Father Pacwa stated. When I originally wrote about this back in 2010, I was pleasantly surprised that the editors of Luther's Works actually stopped by here and left me a comment about this:
Rev. Dr. Benjamin T. G. Mayes said...Was Luther a murderer?
In the early 1980's, Dietrich Emme popularized the theory that Martin Luther entered the Augustinian monastery in Erfurt not due to his experience in a storm, but in order to escape prosecution after killing a companion (Hieronymus Buntz) in a duel in 1505 (Martin Luther: Sein Jugend- und Studentenzeit 1483-1505 [Cologne, 1982]). Emme's work on this point has been widely dismissed in recent scholarship as piling one speculative conclusion upon another (e.g., Andreas Lindner, "Was geschah in Stotternheim," in C. Bultmann, V. Leppin, eds., Luther und das monastische Erbe [Tübingen, 2007], pp. 109-10; cf. Franz Posset, The Front-Runner of the Catholic Reformation: The Life and Works of Johann von Staupitz[Aldershot: Ashgate, 2003], 94, and the response by Helmar Junghans, Lutherjahrbuch 72 :190).
The standard biographer of Luther claims that Hieronymus Buntz died of plague (Martin Brecht, Martin Luther: His Road to Reformation, 1483-1521 [Minneapolis: Fortress, 1985], 47), and this is documented in sources from 1505 (http://books.google.com/books?id=r2hHAAAAYAAJ&dq=Hieronymus%20Buntz&as_brr=3&pg=PA34#v=onepage&q=Hieronymus%20Buntz&f=false).
The "duel theory" relies on one of Luther's Table Talks: "By the singular plan of God I became a monk, so that they would not capture me. Otherwise I would have been captured easily. But they were not able to do it, because the entire Order took care of me" (D. Martin Luthers Werke: kritische Gesamtausgabe[Weimar Edition]: Tischreden, vol. 1 [Weimar: Hermann Böhlaus Nachfolger, 1912], p. 134, no. 326). Yet this refers to the Augustinian order's protection of Luther from Rome in 1518, not a putative flight from prosecution for dueling in 1505.
If Luther's "duel" were true, it would have been a matter of rather public knowledge, both casually, among students and the monks, and officially, both with whatever civil or episcopal authorities were supposedly trying to arrest Luther, as well as because a dispensation would have been required for Luther's ordination (homicide being a canonical impediment for the sacrament of order). In other words, it would be practically unthinkable that when the Roman Catholic polemical biographer of Luther, Johannes Cochlaeus, was searching for data about Luther's monastic career (and coming up with stories like Luther wailing in the choir) that such a "fact," if true or even rumored, would not have emerged.
Dr. Christopher Boyd Brown, general editor, Luther’s Works: American Edition
Dr. Benjamin T. G. Mayes, managing editor, Luther’s Works: American Edition
2:30 PM, MARCH 30, 2010