Name servers that are offline, resolve for other carriers?

[Brook Harty]

I just was informed that cadoj-gwwa.doj.ca.gov was not able to
resolve, I traced it back to doj.ca.gov nameservers are offline,
ns1.doj.ca.gov and ns2.

Now if the servers are offline, and cant provide resolution. Why can
other people? Where is it cached? I tried Verizon and BT, both
resolve.

Is there some dns caching software that everyone is using that I'm not
aware of?

Any ideas, Tired of people saying "It resolves on the desktop
network!", when the customers name servers are offline.

Thanks.