All the same ways I know when Internet comments, outdated books, superstitions, and other humans are bullshitting me.

Sometimes right away, something sounds wrong. Sometimes when I try to apply the knowledge and discover a problem. Sometimes never, I believe many incorrect things even today.

When you Google the new term it gives you and you get good results, you know it wasn't made up.

Since when was it acceptable to only ever look at a single source?

That’s the neat part, you don’t!

Same way you know for humans?

But an LLM isn't a human, with a human you can read body language or look up their past body of work. How do you do his with against an LLM

Many humans tell you bullshit, because they think it's the truth and factually correct. Not so different to LLMs.