To be frank, at all the German airports I have ever gone through, LH has no automatic control over priority boarding. They call for Biz, SEN and *G which are then funelled through a separate gate; thereafter they open up the main automatic gates where all the non-stautus people are queuing.

Since all of the gates are, in fact, only capable of reading the boarding sequence number and name, any Tom, Dick or Harry on his first time on a LH flight and not even being a member of M&M let alone having status can go through priority without this being noticed.

I have never seen visual cross-check of eligibility vs. actual details on boarding pass (at least on domestic and European flights ex Germany).