Might be someone decided to demonstrate a bit of 'incompetence' because they thought shit needed to get out. That's just speculation, though.
Equally possible that someone was just dumb with computers.
I'll give you a real life example, involving my co-workers, one of them is our top IT guy.
We needed to redact some confidential info from some board meeting transcripts (PDFs) that a secretary was sending out to a third party. All the secretary had was Adobe's PDF reader. I informed her, and went to my head IT guy, that we would need to buy some real editing software to properly redact the documents, and that it makes sense for a secretary to have the full program anyways.
He says "she can just use Adobe reader, and highlight it in black"
Me: "but they can just unhighlight it..."
IT boss: 'well then we can put it in protected view"
Me: that's now what protected view is for. They can just shut it off in one click and it's a local setting that probably wouldn't transfer over. This is usually just a safety feature for email attachments. One click, it all it takes. it shows the button at the top of the page to take it out of protected view.
IT boss: whatever, I already told her to do it this way.
So they sent out those files, with the redactions just simply highlighted in black.
This was from an IT "professional." To be fair, the guy is a dumb fuck and BS'd his way into his position, but it's quite believable that would happen in government too.