LiveATC.net is likely how they found out; sending around Executive One Foxtrot is a big deal (although I wonder if there'd been the same reaction/news if it'd been a vehicle incursion onto the runway or some other cautionary go-around). LiveATC can be a nice tool for practice, reviewing phraseology, etc but it's also a constantly running archive of stuff you say on the radio - it's all being archived, and people get busted for doing stupid shit on the radio by that (Controller kid @ JFK comes to mind).
Also, it's the media...they're in search of a story, and the sleepy/screwed up controller is such an easy one to pick at these days (it really doesn't help when people keep fucking up). In a month it'll be something else, remember when it was "drunk" airline pilots?
I think it could be FAA management grandstanding to make it look like they're doing something to these rogue controllers? There's a big gulf between FAA labor and management, the current labor contract with bargaining units expires in 2012 and I'm sure there are those who would like ammunition to have the next one be more restrictive.
Word on the street is the Miami Center sleeper was dimed out by a fellow controller over a personal beef. I hope that's not the case.