V1 ran. Documents generated, rules held, nothing crashed. And every week we ended up asking the same question: why is it doing the dumb thing again, the one we specifically told it not to do. The fix was always the same. Add a rule. Cap the word count on a document. Carve out another exception. A few months in, we had a system that only worked because of a pile of patches, and nobody could say for sure which patch was holding up what. We were checking outputs. That wasn't the gap. What we didn't have was anyone checking independently. We took an agent's own explanation for why it did something as proof it was fine. When something broke, we spent weeks in the same loop: patch it, look again through the same lens, patch again. It took a long time to see that checking an agent through its own reasoning isn't verification at all. The rebuild comes down to one rule: one agent's output is a claim, not finished work, until a second agent checks it independently, not by reading how the first one got there. The same way an inspector doesn't sign off on a plumber's joint based on his notes. They check it themselves. It's the same thing we tell clients about their own processes before we ever touch AI. This time we had to break it ourselves to actually understand it. Anyone else got a rule like that, one you only learned after something broke badly? Curious what it cost you before you figured it out.