It’s not in the article. Unless you’re referring to their speculation:

Then there’s the bizarro version of delete where you’re quite convinced you’ve gone through every single device and deleted your photos permanently, and then a restore from an old iCloud backup or a pernicious little iOS bug resurfaces those photos. Surprise! That appears to be what triggered this latest incident.

Which is not what this bug was about at all.

Yeah it’s bad news reporting from Wired, but people seem to gobble it up as facts.