Hi G.T., here is one explanation. If you go to "Part V" (next-to-last page) of this somewhat long treatise, it discusses ejection and says case strikes on the receiver are typical for the Luger action. It does not mention a correction. Since reading this a few months ago I inspect spent cases from time to time and all are oval suggesting to me a receiver strike on ejection. The pistols are successfully ejecting so I've never investigated correcting it. Whether this is authoritative or not I don't know, but is is a fun read.
http://www.forgottenweapons.com/wp-c...unFacts%29.pdf