If it is true that...

Once the loops on fabricated claims and citations are closed, one may have to start doing real-world things to establish that authors didn’t exist or the events did not happen

and

Doing real-world things to establish that authors didn't exist or the events did not happen is both a lot of work and itself highly unreliable

Then it must be true that...

Once the loops on fabricated claims and citations are closed, the fact-checker is in serious trouble