...but I wouldn't draw too many conclusions based on an oped with an obvious agenda.

Looking at the meager evidence provided in the oped, I don't think there's necessarily an inconsistency between the German intel and the NIE, but I haven't read the actual court report that's referenced, or the May 2008 BND report (if anyone could provide links, that would be great).

To begin with, the NIE conclusion was limited to Iran's work on warhead design and testing and not other, necessary, parts of a weapons development program. The article, however, makes no mention of that aspect in the NIE. Instead, it quotes from the report:

the development of a new missile launcher and the similarities between Iran's acquisition efforts and those of countries with already known nuclear weapons programs, such as Pakistan and North Korea
Work on a missile system does not conflict with the NIE conclusions on warhead work, nor does nuclear-related acquisition efforts. There is a lot of selective quoting about "development of nuclear weapons" but what does that mean exactly? The oped leaves us wondering and assumes we will draw the appropriate conclusions after leading us partway down the path.

That Iran is continuing work on enrichment, building a research reactor (which is, coincidentally, a perfect design for plutonium production), and working on delivery systems is enough for many to conclude Iran is "developing nuclear weapons" even if there isn't currently an effort on the actual warhead. So until I see more information, I don't see any serious conflict between the NIE and what is quoted in this opinion piece.