Comment by starpilot

Now, imagine you have 5,000 such checks in millions of lines of flight control system code, many of them interdependent, and you have to fly the ship to test each one. You need to schedule time with the test pilots (who have lives of their own) and get the data dump from IT post-flight. It's aerospace so all this undergoes review, documentation, and signoff, and it all takes time. How do you prevent a single check from slipping through? It's not easy. These software engineers and others in the process screwed up, but it's a failure of processes and not just forgetting a conditional statement.