[Unroasted6154]

What makes you think it was completely untested? The condition that triggered the null pointer exception was obviously not tested, but it doesn't mean it didn't have tests or even 100% unit test coverage for the coverage tools.

In addition it looks like the code was not ready for production and the mistake was not gating it behind a feature flag. It didn't go through the normal release process.

[piva00]

If Google spent Moon-landing level of money in their quality/deployment infrastructure I expect a much better coverage checker than "100% unit tested", they are famous for having a whole fuzzing infrastructure, coverage analysers for more complex interplay of logic is something I use daily in a non-Google levels of spending (even though still a big enough corporation) which often reminds me that I forgot to write a functional test to cover a potential orchestration issue.

I don't think "completely untested" is correct but tested way below expectations for such structural piece of code is a lesson they should learn, it does look like an amateur-hour mistake.

[Unroasted6154]

The main issues to me seem to be that the code was not gated by a flag when it was not ready to be used, thus skipping a lot of the testing / release qualification.