Furthermore, this happens so often, so frequently, in so many high profile cases that even my 80 year old mother knows this "secret hack to unredact a pdf".
If you are CIA / FBI / Court / Lawyer or professional full time redactor of documents you should know that the highlighter doesn't delete the text underneath it.
I think the more likely cause was precisely that it wasn't a technical professional/lawyer/writer doing the redacting, but someone in the administration or close to it that has no idea how to redact information correctly.
If you are CIA / FBI / Court / Lawyer or professional full time redactor of documents you should know that the highlighter doesn't delete the text underneath it.