It's quite light on specifics. It should have been straightforward for the author to excerpt some of the prompts he was submitting, to show how innocent they are.
For all I know, the author was asking Claude for instructions on extremely sketchy activity. We only have his word that he was being honest and innocent.
(My bet is that Anthropic's automated systems erred, but the author's flamboyant manner of writing (particularly the way he keeps making a big deal out of an error message calling him an organization, turning it into a recurring bit where he calls himself that) did raise my eyebrow. It reminded me of the faux outrage some people sometimes use to distract people from something else.)
It is when the other side refuses to tell their side of the story. Compare it to a courtroom trial. If you sue someone, and they don't show up and tell their side of the story, the judge is going to accept your side pretty much as you tell it.