I fact I do have suspicions that a lot of German brewing practice is designed to drive a cart horse over the spirit of the law whilst staying exactly within the letter of it. An article in a recent Brauwelt highlights the various possibilities that exist for variety whilst staying within the law. An interesting one I hadn't heard of has been translated as follows:
"reviving historic beer styles which were customarily brewed in certain parts of Germany before the Purity Law came into force in those areas and for which the legal status of traditional speciality beers, exempted from the obligation to comply with the Purity Law by a provision of the current German brewing industry regulating legislation, can therefore be claimed"It seems there are exemptions for historic local specialities. So surely it's time for German brewers to study some of Ron's works.