Here's the full decision, which (like most decisions!) is largely written to be legible to non-lawyers: https://storage.courtlistener.com/recap/gov.uscourts.ded.721... The core story seems to be: Westlaw writes and owns headnotes that help lawyers find legal cases about a particular topic. Ross paid people to translate those headnotes into new text, trained an AI on the translations, and used those to make a model th…
Westlaw protects them because they are the "value add." Otherwise their business model is "take published decisions the court is legally bound to provide for free and sell it to you."
An LLM today could easily recreate the headnotes in a far superior manner from scratch with the right prompt. I don't even think hallucinations would factor in on such a small task that was well regulated, but you can always just asterisk the headnotes and put a disclaimer on them.