I agree with Sara and Kevin, as well. While Kevin uses the idea that we should be "do whatever research may be required to ensure that they have it correct," I'd be happy with just being sure beyond a reasonable doubt. I was on a jury and the definition of reasonable doubt was much hazier than I'd thought before. Sure, you can have some sort of doubt, but if it's beyond your own idea of what's reasonable, then you have an unreasonable doubt and can ignore it. I'd still not go just off of a forename; I'd try to find a pronoun somewhere.
Somewhat looser than the situation discussed by Julie Still and us being "Fair witnesses"; if a trained fair witness sees the front cover of a book is green, they won't say that the back cover is as well. I'd say it's a reasonable extrapolation.
Still, J. M. (2011). Librarian as Fair Witness: A Comparison of Heinlein's Futuristic Occupation and Today's Evolving Information Professional. LIBRES: Library & Information Science Research Electronic Journal, 21(1), 1-9.
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