The Crowdstrike report explains why it crashed, but not how it passed final end-to-end testing. There appears to have been many tests of piece parts (unit testing), but that's not the same as testing the full system.

I would think all the end-to-end tests of the full system would have been instantly detected the problem and prevented it, because it would have failed all the end-to-end tests.

Did I miss something? Did they never test the complete system as deployed? Looks like it, but maybe I misunderstood something.