Hmm, that's an interesting idea. But it's the classifier that is triggering, and it triggers specifically on Claude's output. So I think the /dev/random case wouldn't work, because that gets Claude into the state of just reproducing the entire text from the original again.
It doesn't always get flagged. Single pages are almost always okay. Running a program that sequentially runs single pages through the API is often not okay - I wrote a program in the early 4.x days before the rule came in, that's how I hit it first. But I've also had entire articles go through just fine recently in a Claude Code session (I'd forgotten about Anthropic's rules!), and then others where I get classifier errors by page 4.
The Mistral OCR errors were small in size. Single sentences, formatting errors, paragraphs with newlines. So this was a genuine proofreading job with small changes. For the most part Mistral is actually good, but I can't have it just inventing sentences in the middle of a document. That's where the Claude proofreading pass was most helpful.