LLMs routinely hallucinate sources. I guess that's why some people feel that way.
For example, is glyphosate the active ingredient in roundup? there are studies that suggest not. I can't remember the university, i can remember the rough decade (2010s). all i know for sure is that someone showed that glyphosate isn't the active ingredient, really.
Deepseek can't find it. ddg doesn't come up with it immediately. I might try "deep think" mode on some other AI later, or use an older LLM model i have locally to see. I have the pdf, i just didn't rename it to be searchable! doggone it.
Source hallucination has also come down tremendously.