How would a Kraut have any criminal-law jurisdiction over an American Offical?
The Germans won't have jurisdiction over any US citizen unless the attorney general allows legal paperwork to move forward to take possession of the guy. For the remaining two years...this will not occur. For the German left...this is all a media game and cheapens law to the point of being a "bartered lady in a red-light district" (I tried to say this in a dignififed manner).
What you may notice over the next twelve months is a direct attempt to have customs and legal officals on Ramstein to monitor aircraft and passengers flying in and out of the port there. This will simply be a first-step.
As for any jurisdiction....the moment that the human rights court opened up via the UN...in Europe...this whole mess went into a different view. These people actually believe that they can bring this earth to a better place...by charging people in court. The amusing thing...is that they won't go after Mr. Kim....nor Castro....nor any leftist dictator out of Venezuela...or even a Russian president who orders the personal execution of a reporter. Nor would they even go after business men who plunder companies throughout Europe and just walk away...leaving bankrupt organizations and bank officals hanging.
This is the mighty fine world we live in....and beats watching a Jerry Lewis movie on a Saturday night.