Silent Deletion

Silent deletion is when an AI assistant edits a file and quietly drops a block of code you needed — a validation step, an error handler, a feature toggle — without calling attention to it. The remaining code compiles and looks like an improvement, so you merge it. A week later, a user reports that something that used to work doesn't anymore, and you can't find the commit where it broke. This happens because large language models, when asked to rewrite a function, sometimes output their 'best version' of that function rather than a true edit. Anything they don't see the purpose of gets optimized away. The fix is cultural, not technical: treat AI diffs the same way you'd treat a pull request from a new contributor. Read every removed line, not just the added ones. Ask 'why was this here?' for everything that's gone. If the answer is 'I don't know,' restore it and investigate before deleting. Good version control is your safety net — never accept a diff you haven't compared line by line against the previous state. Our review checklist includes a specific item for this because it's the single most underrated vibe-coding hazard.