I don’t think it’s so clear cut… Even the most adamant “facts are immutable” person can agree that we’ve had trouble “fact checking” social media objectively. Fluoride is healthy, meta analysis of the facts reveals fluoride may be unhealthy. The truth of the matter is by and large what’s socially cohesive for doctors’ and dentists’ narrative, that “fluoride is fine any argument to the contrary—even the published meta-analysis—is politically motivated nonsense”.
You are just saying identifying "knowledge" vs "opinion" is difficult to achieve.
No, I’m saying I’ve seen reasonbly minded experts in a field disagree over things-generally-considered-facts. I’ve seen social impetus and context shape the understanding of where to draw the line between fact and opinion. I do not believe there is an objective answer. I fundamentally believe Anthropic’s explanation is rooted in real phenomena and not just a self serving statement to explain AI hallucination in a positive quasi-intellectual light.