If it is Just a Half-Dozen or Seven Bad Eggs Why is this happening?

Three key witnesses, including a senior officer in charge of interrogations, refused to testify during a secret hearing against an alleged ringleader of the Abu Ghraib prisoner abuse scandal on the grounds that they might incriminate themselves... ...That all of the prospective witnesses called up by prosecutors invoked the military equivalent of the 5th Amendment right against self-incrimination indicates that key players in the abuse scandal may be closing ranks to save themselves and one another... ...Eugene R. Fidell, president of the National Institute of Military Justice, said no soldier is allowed to invoke his 5th Amendment right against self-incrimination unless he knows his testimony would leave him open to criminal charges. "You can't assert it unless you have a belief that there is some criminal exposure," he said. "That's why people do it." Fidell said he had never heard of a case where every prosecution witness called to the stand refused to testify, but then said, "I can't say I know of any case that is like this one either." He added: "People take the 5th out of an abundance of caution. People are aware of their right not to incriminate themselves. That's been hard-wired into military justice for several decades."