I never recall reading anyone arguing that Luther was not the sole author of the Ninety-five Theses. The notion that the Theses has no historical pedigree until one hundred years later appears to be some sort of variation of the argument put forth by Erwin Iserloh: The Theses Were Not Posted: Luther Between Reform and Reformation. Iserloh held the Ninety-five Theses weren't nailed to the Wittenberg church door, but rather mailed to particular ecclesiastical superiors. "Luther did not post the Theses but only sent them to Archbishop Albert of Mainz and Bishop Jerome Schulz of Brandenburg, the appropriate representatives of the church, for their approval" [LW 31:23]. Iserloh was responded to by Kurt Aland, Martin Luther’s 95 Theses (St. Louis: Concordia, 1967).
The discussion got a little more interesting when a new CA member joined in. I responded to some of the charges made. In essence, the position of Iserloh was being put forth as historical fact (via Richard Marius). I responded that basically the nailed or mailed controversy comes down to whether or not Melanchthon can be trusted as presenting reliable history. Roman Catholic scholar Franz Posset has recently written quite convincingly that Melanchthon's memoirs of Luther are to be trusted more or less, but yet states, "Did Rorer and Melanchthon concoct the Posting in good faith? It looks like it" [The Real Luther, p. 23]. I'm not so sure though that "it looks like it" settles anything. I find it curious how Posset painstakingly argues for the credibility of Melanchthon, but then decides he can't be trusted on this issue.
In response to this, Melanchthon was villainized and his entire career was presented as completely untrustworthy. Now, anytime someone from church history is completely villainized, that should send up a red flag that a caricature is being put forth. People from church history are usually a mixture of successes and failures, sins and virtuous acts, good and bad theology, etc.
In regard though to the issue of nailed or mailed, the following argument was made:
It has been stated here on this thread that the matter of whether Luther ever did any “nailing” rests on the honesty (or dishonesty) of Luther’s right hand man, Philip Melanchthon. I disagree. This ignores the point made by Marius which I included in my last post. Marius made it clear that the only way for Luther’s writings to be consistent with history would be if that history didn’t include any kind of ‘nailing’. Why would Luther suggest (in early November) that he didn’t want the Elector to become aware of the 95 Theses when he himself had (supposedly) affixed them to the doors of the Wittenberg Church, at least several days earlier, where they would certainly be brought to the attention of the Elector? Furthermore, if the issue is to be determined by Melanchthon’s honesty, then would actual evidence of his dishonesty on a very important matter mean that there was never really any nailing?
I responded again, pointing this person to the fact that it looks like Marius was simply parroting Iserloh's arguments and appears to not have even considered the argumentation of Kurt Aland. Now what bothers me the most about the position of Marius is he seems completely ignorant of Aland's counter-argumentation. If one is going to present scholarship, shouldn't one be at least be familiar with the counter arguments as well?
The letter to Spalatin, which is from the early part of November 1517, is of special importance. Definite conclusions can be drawn from it: Luther answers Spalatin's inquiry why he did not send the Ninety-five Theses to the court. Spalatin therefore at least must have heard about the theses by that time and perhaps was already in possession of a copy. Moreover, the theses were already known to a somewhat large circle, since Luther speaks of "the many" who assumed that the elector was behind them. If this was the case in the very early part of November, there can be no other explanation than that "the many," just as Spalatin and the court, knew the theses from the posting on the door of the castle chapel from which copies were circulated. In the early days of November - the letter was written, at the latest, on 5 November - such an echo could not have been caused by Luther's private circulation of the theses, even if he had begun this immediately after 31 October. We have no information concerning this. At any rate Spalatin did not receive a copy; it is precisely because of this that he complains [Kurt Aland, Martin Luther's 95 Theses, with Pertinent Documents from the History of the Reformation (St. Louis: Concordia Publishing House, 1967), p.18].If it turns out the Wittenberg door story is factually inaccurate, well, so be it. There are number of Luther myths, some perpetuated by Protestants, some perpetuated by Catholics. For Reformation Day, I actually gave a lecture on the Reformers to a group of Protestants favorable to the Reformation, and I spent the first 15 minutes or so pointing out that the major Reformers were men with failures, faults, and sins, and also that some Protestants had gone (or do go) too far in honoring their memory (while on the other hand, some go to far in vilifying their memory). For me, the nailed of mailed controversy is a silly debate. If it were determined that Iserloh's argument was the actual historical situation, so be it. It doesn't change the fact the the Ninety-five Theses was, as some consider, the first mass-media event. The Theses caused quite a controversy whether they were nailed or mailed.