I hope @CorelliumHQ and Apple will find an arrangement. Corellium is an awesome piece of software that really ease research. It promotes iOS, its kernel, and development in many ways. It is even included in IDA Pro as a debugger now!
There are processes to help, like code review, unit tests, automatic regression tests, manual ones, internal and public beta tests, etc. But sometimes a bug get through the mesh of the net all the way to @MacRumors.
I absolutely don’t think the last High Sierra bug is a backdoor or intentional (responding to some comments on my previous tweet). It is just a mistake illustrating the complexity of maintaining such a huge software code base. Anytime you change anything you may introduce bugs.
Seriously, the quality of macOS High Sierra is a shame. I really don’t understand how that root login without a password story could happen. Especially when you consider all the good security engineering around (SEP, code signing, sandbox, entitlements). I feel sad.