Just because I've read a book, doesn't mean I understand it. So if I write something on a book that is wrong, it doesn't follow that I didn't read it.
This misunderstanding can be blatant, or subtle. It's like reading a poem that is difficult. I have to go over it several times. Eliot's Quartets are like that. Wallace Stevens is even worse---The Blue Guitar and Emperor of Ice Cream come to mind. And readings change over time and my experience...
CG