An appeal to authority is entirely appropriate if that authority is indeed an authority on the topic discussed. The logical flaw you allude to only fits if dvt

An appeal to authority is entirely appropriate if that authority is indeed an authority on the topic discussed. The logical flaw you allude to only fits if dvt would have said e.g. "I'm right because Lady Gaga said the same argument." While Lady Gaga is an authority, she isn't on the theory of justice.