Whatever happened to "alleged"?

In all the accounts I read in the MSM, Plame's status as a covert CIA operative is reported as if it were an established fact. That a "leak" of that status took place is also reported as if it were an established fact.

When was it established as fact that she was covert?

Now I must confess that I am at a loss as to why her status wasn't conclusively determined within a day or so. How hard can it be for a prosecutor to get the CIA records and depose the appropriate person at the CIA?