I think he is trying to say, the reply indicator should reference the URL the reply was directed to, not the browser URL (which it does now).
As such, there is nothing from a user perspective to help you see what post the reply is directed at without clicking the indicator. And even when you do click it, it routinely fails to show you the appropriate reply when using the experimental reply expansion (which we realize is marked as experimental, but has been marked that way for many versions now)