Definitely no. The "fake" here is about certainty that no insurance payout would occur in case of issue, meaning for example an oil tanker accidently dumping tons of black goo onto some english seaside resort, no compensation would come out of anywhere.

How reliable is liability insurance for that sort of thing, generally speaking?

Quite. The real insurers are large, old, and have long made a name for themselves in this regard. https://en.wikipedia.org/wiki/Lloyd%27s_of_London

So existing legacy monopolies are real and all newcomers are fake. Got it.

Nah. The smaller new ones reinsure via folks like Lloyds. It’s quite complex.

The company in this article could have done that, but they forged documents to avoid it. They had no intention of covering accidents - it was just plain fake to get these ships into ports.

They were not truly insured.