The title in the original Deutsch version is: “J’accuse! Von einem Deutschen.”

Which means that “I accuse! By a German” is the full title. And not the translator neglecting to put in the name of the original author, as it looked at first glance (though they certainly did.)

The use of J’accuse! is of course a reference to Zola; but while Grelling was similarly accusatory, he wasn’t accusing about the same thing. Specifically he was accusing the German state of being responsible for the Great War that had just started the previous year (it was published in 1915).