That’s true if it’s the same organization doing both things. In the case of aircraft accidents, we deliberately separate out the investigators from everyone els

That’s true if it’s the same organization doing both things. In the case of aircraft accidents, we deliberately separate out the investigators from everyone else precisely to avoid that problem. The investigators make recommendations for actions that should be taken to prevent future incidents of the same type. Firing the pilot doesn’t accomplish that, so the investigators didn’t recommend it. That doesn’t mean that firing the pilot is inappropriate though, only that doing that wouldn’t prevent future accidents of this type. The procedures are never finished. They’ll be updated as needed for as long as anyone flies the airplane. The final revision could be a century or more from now, long after the airplane is out of active service. The updates it receives in that time depend on what accidents happen during that time, as well as how the systems change during that time.