More complex than that:

This is India-centric, and talks about a case that was hot 2y ago, not now, but is a good overall review of realexistierende extradition policy.

http://blogs.hindustantimes.com/foreign-hand/2011/06/30/getting-real-about-extradition/

In summary, some countries never extradite their own citizens, and some others very rarely. Deutschland is one such. A conspicuous recent exception has been Britain to America - which was written about in every British newspaper when almost identical cases of financial crimes tangentially related to the Financial Crisis led to Brits being extradited to the Empire but not Americans to Airstrip One.

(This doesn't mean he is entirely safe from prosecution in Germany either. I can see an argument for Germany to claim universal jurisdiction and try him that way, based on EU pedolaw. But that is for the German government to decide, not the US.)