The guy is German, and the German language traditionally uses generic masculine pronouns, although that has become a big political issue in the past years. Some new gender-neutral forms have developed, but some of them have even been banned by the "center"-right-wing clowns in two state governments, and it's all a bit of a mess. The guy probably thoght "they" in English is a similarly experimental concept, and while it's still dumb and he should just try to be as inclusive as possible, it's probably not a matter of him purposefully excluding women from the documentation.