Ten to one he was CIA - his silence speaks volumes ...
Odds are he was fed/betrayed to Cuba by one of our wayward leftwing congress critters for the purpose of giving Cuba a hostage and making a deal with Cuba to drop sanctions...the effort to return the Wasp Network spies started before Gross was arrested by the Cubans. It apparently started at least by April 2009 when Castro got a visit from the scummiest of our congresscritters; Gross was arrested in Oct 2009 and I wouldn’t doubt it if he’d been betrayed by someone with access to classified info and a monetary interest in lifting the embargo.