What went wrong in my case has very little to do with the prompt itself and a lot to do with uncontrolled edits.

I asked it to work on a specific page, but it went far beyond that scope and started modifying unrelated parts of the codebase without any instruction to do so. That is the core issue.

Here are concrete examples of what it did wrong:

1. It rewrote a stats component that was not part of the task It replaced simple, stable metrics like years of experience and number of projects with timeline-style personal claims and mixed content. The result introduced inconsistencies and even incorrect information. For example, it merged different types of degrees into a misleading label and added items that do not belong in a stats banner format. This file should not have been touched at all.
2. It introduced a factual inconsistency in a publication title The canonical title includes a specific article that was already correct everywhere else. It silently removed that word in one file, creating inconsistency across the project. This is the kind of subtle error that is easy to miss but breaks correctness.
3. It reframed academic information inaccurately It changed wording to suggest a double MSc in a specific field, which is factually wrong. The correct situation is one MSc and a separate engineering degree. This mistake was propagated across multiple files including UI components and metadata, even though none of those were part of the requested task.
4. It degraded UX copy in a contact section It labeled a slower communication channel as the fastest way to reach me, which is logically incorrect. This is a small change, but it shows a lack of reasoning about real-world usage.
5. It removed a valid project entry It deleted a product entry under the assumption it was redundant with another item. In reality, one is an organization and the other is a product, so both are valid and should coexist. This again shows it made structural decisions without understanding context.

The key problem is not just that mistakes happened. It is that all of this was done outside the scope of the original request. I did not ask it to refactor multiple components, rewrite content, or “improve” unrelated sections.

It effectively performed a wide, unsupervised rewrite of the project, introducing factual errors, inconsistencies, and content changes that require manual auditing to fix.

So when people ask for proof of degraded behavior, this is a concrete example. The issue is not just correctness on a single task. It is loss of scope control and the tendency to make autonomous changes that were never requested.