They are turned over directly to Cuban authorities, so yes, the government does find out. They are then liable to be charged at a minimum with illegal exit, that is leaving the country without government permission, which carries 1-3 years. Of course some of them may also be charged with organizing an illegal exit which carries 2-5 years.
Cuba did agree, when the repatriation program was negotiated in 1995, not to apply the illegal exit laws to repatriated Cubans. However the laws have not been repealed, and there have been a couple of reports of the laws being applied anyway. And there are plenty more crimes they are likely to be charge with anyway, such as criminal association, or theft of government property; hey that truck, old as it was, was property of the state.
In any case, as high profile as this was, these guys are likely to get the book thrown at them.
