Kingu - professional publishers aren’t actually doing their jobs. They’ve been caught before doing this, and this isn’t a one time thing.
You would think that a professional publisher would at least do a search on the book title and name to see if it had been published before.
It’s the same with teachers too. You really think they check your sources? No, they don’t. I had one teacher in 4 years of school care enough to check my sources. If it looks good - that’s all they care about - whether the i’s are dotted and the t’s are crossed and whether the format is the one that they prefer.
Think about this for a minute - teachers are willing to tolerate, even ignore entirely erroneous citations if they look good. It was depressing. Me and the teacher who did check became good friends.
As it disclosed in the story, the title and author were purposefully left off the manuscript. Hard to do a search for a book title if it is not included. But again, unsolicited manuscripts typically get returned unless it is submitted in the abbreviated form.