A recent issue emerged in an app built with React due to an infinite recursion bug caused by an AI coding agent. The problem started when a comment warning about the dangers of removing a `readOnly` prop was deleted during a UI overhaul. This prop was crucial for preventing recursive rendering of header and footer components in the app’s editing interface. When the AI agent removed it, there was no longer any signal to indicate that this change was unsafe. After deploying updates that included new features, users began experiencing browser crashes. The app appeared to function normally at first, but memory consumption surged until the browser eventually froze. The new `<Activity>` component in React 19.2 was designed to handle hidden UI elements efficiently, but in this case, it inadvertently concealed the underlying bug. The component allowed the app to render an infinite tree of components in the background without immediate crashes, making the debugging process particularly challenging. The author spent days tracing the issue, initially suspecting a problem with the Motion library used for animations. However, the real breakthrough came when removing the `<Activity>` wrapper from the footer editor. This revealed the infinite recursion immediately. Ultimately, the author concluded that comments aren’t a reliable substitute for tests, especially in a codebase where both human developers and AI agents contribute. Proper testing would have caught the issue before it became a significant problem.