
I think this is a weak argument.  The fact is, there are *two* references to
Jesus in _Antiquities of the Jews_, one of which has unquestionably at least
been altered by Christians.  Origen wrote, in the third century, that
Josephus did not recognize Jesus as the Messiah, while the long passage
says the opposite.  There is an Arabic manuscript of _Antiquities of the
Jews_ which contains a version of the passage which is much less gung-ho
for Jesus and may be authentic.
   There is no question that Origen, in the third century, saw a reference
to Jesus in Josephus.  There are no manuscripts of _Antiquities_ which
lack the references.

It is possible that it was fabricated out of whole cloth and inserted, but
I don't think it's very likely--nor do I think there is a consensus in
the scholarly community that this is the case. (I know G.A. Wells takes
this position, but that's because he takes the very small minority view
that Jesus never existed.  And he is a professor of German, not of
biblical history or New Testament or anything directly relevant to
the historicity of Jesus.)