When a given demographic is a dominant presence in a given area (not necessarily work, it can be anything), there is a tendency for they demographic to start making assumptions about other demographics.
Isn’t she the one making assumptions, though? Specifically, the “prejudice and stupidity of the person indirectly insulting her” part? I mean, is that really the only possible explanation?
What other reason would you suggest as to why he would assume that he knows more than her or that she couldn’t be the person that he’s referring to? Clearly he didn’t even know her name yet so what did he have to go by to draw those conclusions? It obviously wasn’t her lack of knowledge on the subject that they were discussing now was it?
Clearly he knew her name, though. He just didn’t know the woman he was speaking to was the woman whose work he was recommending.
And he made that assumption based on? Because, again, we know for a fact she didn’t sound ignorant on the topic.