This isn't even the case though. The site specifically says that the documents, all of them, are public. They just happened to have noticed they screwed up and

This isn't even the case though. The site specifically says that the documents, all of them, are public. They just happened to have noticed they screwed up and published some they shouldn't have, and are now going after someone who downloaded the entire set. This was not prohibited in any way that was documented on the site,and the language that was on the site made it sound like it was allowed. Since the theme is analogies how about this one: someone puts a box labeled "free stuff" in front of their house. You dig through it and find something of value. You take it and go home. A few days later your house is raided because the owner of the house put in something valuable by mistake and is now claiming they never intended for anyone to take anything that wasn't visible from the street. Since you dug through the box, they are charging you with theft.