I wanted to give a short update regarding the suggestion to contact Dr. Böse.

He replied very quickly, I’m quoting only the first paragraph of his message:
“Voraussetzung dafür, dass ich einen Vorgang betreuen kann, ist die Zuständigkeit deutscher Gerichte. Diese geht dann in der Regel auch mit der Anwendbarkeit deutschen Rechts einher.”
In summary, he explained that he cannot take the case because there is no German jurisdiction involved (Austrian carrier, no German departure/arrival point, no connection to German courts). He also added that while he technically could send a demand letter, airlines generally ignore such letters if the lawyer has no jurisdiction to follow up with actual legal action in that country. According to him, doing so would be ineffective and not a serious approach.

He also pointed out that pursuing legal action abroad can be expensive and that many countries do not follow the German principle where the losing party pays all costs. So before engaging a lawyer outside one’s home jurisdiction, it’s important to clarify the potential cost exposure.

That’s the update for now .
BTW Does anyone here know a similar aviation lawyer in Austria who deals with these kinds of cases?