The German legal system to a large degree has the extent and actual interpretation of the written laws determined by case law. I don't know if this is a landmark case, but if it is (which I would assume) then this is very much outlawing this practice.
that is not correct. germany does not use the common law system where case law is binding, but the civil law system where each case is taken on its own merrits against the law as it is written. past cases are only used as advice to help interpret a new case, but judges have the freedom to not follow that advice.
