All models hallucinate. The likelihood of hallucinations are however strongly influenced by the way you prompt and construct your context.

But even if a human went through the documents by hand and tried to make the analysis, they're still likely to make mistakes. That's why we usually define the scientific method as making falsifiable claims, which you then try to disprove in order to make sure they're correct.

And if you can't do that, then you're always walking on thin ice, whatever tool or methodology you choose to use for the analysis.