I think we've established now that she's not an actual professor though, right?
Indeed. I think the best possible case for DB's credibility is that she in fact knows nothing about academia, did have a brief visiting professorship (that could be checked by a FOI to the institution), and doesn't understand how professor titles work.
To me that would be a less extreme allegation than that she's an academic who scrubbed her online presence which would be basically impossible to do anyway. But it would screw up her future sitting on tribunals and stuff because having had it pointed out that she isn't entitled to use professor, she can't just continue.
So racking my brains to make any sense of all this, I wondered if this is NC's way of letting her know they know and offering her a chance to fall on her sword. Which she did.
How can they not know? Dr CE has an academic background herself. She knows what a publication record looks like. As soon as someone suggested she look up the Prof, she will have twigged.