A literary critic or reviewer or some such breed, had that same argument with Isaac Asimov about one of his, Asimov's stories, AND CONVINCED HIM. Asimov then went around claiming that he, the author, did not know and could not be expected to know what his stories were about.Ray Bradbury used to tell a story about some convention or talk he had given where, when it was over, a fan came up to him and argued with him about the meaning/message of "Fahrenheit 451". The guy kept claiming that Bradbury, the AUTHOR OF THE BOOK, was wrong in his "interpretation" of the meaning of the book.
One of the lines from that argument, quoted by Asimov (whose memory was even better than mine so you can mortgage the house on the quote being accurate), was "what makes you think, just because you wrote the story, that you know anything at all about it?"