The only way this happened is the Judge is corrupt/blackmailed.
https://www.zerohedge.com/news/2019-03-26/smollett-charges-dropped-after-emergency-court-appearance
Excellent point. Maybe this is why Geragos is under indictment with Avanetti. But it also could have been bait to find other FBI agents part of the Cabal. Remember State's Attorney Foxx was reaching out to the FBI. Could Smollett still face Federal charges?
If all the charges were dropped, then double jeopardy would not be a defense against Federal charges being brought IMO.