> If they had nothing to hide, they wouldn't be hiding everything. If that was a criminal case, this kind of behavior would be taken as a evidence of guilt.

No, it would not. First, dictatorships hide things all the time, whether there is something or nothing. It's just how they operate. (Many democratic governments do to btw. How often do we need freedom of information requests just to find out that it was totally benign, the government just stone-walled because they could).

Second, not saying anything is not evidence of guilt in any criminal case in the civilized world. Everyone has the right to silence.