I realized that this is something that someone with Claude Code could reasonably easily test (at least exploratively).

Generate 100 prompts of "Famous (random name) did (random act) in the year (random). Research online and elaborate on (random name) historical significance in (randomName)historicalSignificance.md. Dont forget to list all your online references".

Then create another 100 LLMs with some hallucination Checker claude.md that checks their corresponding md for hallucinations and write a report.md.