That's a tough one to translate - so tough that I tried Google for some assistance. Most of the results were about Steeley Dan who apparently made an album called "Pretzel Logic" in the 70's. However I found a really interesting link to a cult called "The Kingdom" which was apparently popular at the turn of the 20th century. One of the pages is called "pretzel logic". I guess the Rawat cult isn't the only one guilty of logical contortions, but that's not really news.http://www.fwselijah.com
http://www.fwselijah.com/pretzel.htm
I've only skimmed through, but what I found so intriguing is first of all the similarities despite the generational and doctrinal difference. It's all there, the infallible leader, the arrogant feeling of specialness of the members, the abuses, etc.. Secondly, the way the website is set up – the disclaimer on the first page – reminds me in parts of both EPO and PRMI. The authors seem to have gone through a similar process.
About your translation: Man könnte 'eine Leistung von verdrehter "Bretzel" Logik' sagen, aber ob das dir weiter hilft? Marion meinte: 'Das Wort im Mund umdrehen'.