They have the wrong name. As I noted below in my first article that dealt with the history of sensational claims from Talpiot, “The Talpiot Tombs: Again, and Again and Again,”—early on R. Bauckham caught the fact that the name inscribed on the ossuary read by Simcha Jacobovici, Dr. James Tabor, et al. “Mariamne” should be read “Mariamenon.” The inscription reads: “Mariamenou e Mara.” The genitive of Mariamne would be Mariamnes (final letters eta, sigma). Hence Mariamenou comes from Mariamenon.
Repost from below "The Talpiot Tombs...":
“Belonging to Mariamenon who is Mara” [Genitive of Mariamenon with a second name “Mara” (a short form of Martha)]. This has been suggested by R. Bauckham [http://benwitherington.blogspot.com/ (See Wednesday February 28, 2007)]. The Discovery Channel film proposes to read Mara as the Aramaic word ‘the master’ (as in Maranatha). Bauckham later wrote: "But, since we know that Mara was used as an abbreviated form of Martha, in this context of names on an ossuary it is much more plausible to read it as a name. This woman had two names: Mariamenon and Mara. It could be that the latter in this case was used as an abbreviation of Mariamenou, or it could be that the woman was known by Mariamenon, treated as a Greek name, and the Aramaic name Mara, conforming to the common practice of being known by two names, Greek and Semitic" [http://www.christilling.de/blog/2007/03/guest-post-by-richard-bauckham.html].
Note that R. Baukham’s early notice that they had the wrong name did not phase the defenders of the "documentary" last night. Both Jacobovici and Taber misrepresented the name either due to poor scholarship or… well I think the rest would be transparent enough. It is a little hard to believe that they would not know this after months... years in some cases of studying these inscriptions. See also: http://ntgateway.com/weblog/labels/Naassenes.html.
The Mariamne connection to Mary Magdalene was already one of those great big “ifs” alluded to by Bock on the Koppel program that followed. Since it is Mariamenon… as this is weighed by scholarship today, let’s just say that “if” has really grown.