I didn't hear that they were charged with contempt of Congress. If they refused to answer questions unless they take the fifth or there is a claim of executive privilege, they are bound to answer the question or be found in contempt. Why would they not have been found in contempt?

Maybe because the whole thing is a dog and pony show put on in an effort to get these senators re-elected. None of them are really interested in finding out anything. They are just interested in getting their faces in front of the American public and trying to convince us that they are actually doing something other than wasting out time and money on a re-election scam.