The article describes that a government body is using this library to generate indictments. In that situation, you do not want something that is mostly usually correct. Indeed, they asked the author for a strict version that does not try to guess the declension of unknown names based on their suffix, presumably so that they can just not decline them, which is better than picking the wrong declension 0.05% of the time.

By the author's own evaluation the solution proposed is not always correct either. The real danger would be the LLM hallucinating a different name altogether.