In 2005 the University of Konstanz used a passage in their dissertation rules to pull the doctorate out from under him: a doctoral title can be rescinded when the behavior of the person after obtaining the doctorate demonstrates that the person is unworthy of bearing such a title. Schön objected on the grounds that his dissertation was okay, the fakes only came after.
It has taken the university 5 years to decide to stand by their decision. While I applaud the decision, I do wonder if it really needed five years for this.
Schön's only recourse now would be through the court system, and that may take even longer. Spiegel reports that in a recent case involving the University of Bonn, it took the courts eight years to decide in favor of the university rescinding a doctoral title.