I was an editor of a small print publication and this happened to me once. The caption below a photo was something like "Please tell me this isn't a stupid picture of XYZ" (can't remember what it was) as a joke to the copy editor who would eventually see it an laugh at how hilarious I was. Of course it slipped by because it just looked like a normal caption.

I'm not sure these examples advance this article's point too far-- incidents like these could have been avoided by more clearly marking that the text was a placeholder.