Congress is apparently going to actually hold hearings on the destruction of the CIA tapes that were ordered not to be destroyed. Jose Rodriguez, a former CIA official, has insisted that he won't testify unless he's offered immunity, on the premise that anything he says can be used against him.
Well, yeah. That's kind of the point. The hearings are to determine if there was any impropriety going on, and not just stupidity. The Executive Branch, of course, wants the Courts and Congress to not do anything and let the Justice Department (an Executive Branch department) do its own investigating.
Here's the problem. It might just be that the destruction of the tapes was inadvertent, and nothing improper actually occurred. But with the credibility issues this administration has based on its past actions, statements, backtracks, misstatements, hemming and hawing over issues, any conclusions that the Justice Department might come to (a justice department that had several of its attorneys fired for not prosecuting Democrats hard enough or for daring to prosecute Republicans) that are not "the Executive Branch Committed High Crimes or Misdemeanors" will not suffice. And the Executive Branch knows that the Justice Department will drag its heels until it's too late to effect any actual punishment on any malfeasance that may have occurred.
Jose Rodriguez wants immunity. Again, this could be merely a statement that he wants to ensure that he's safe to speak freely. But the perception is different. The perception is that he wants immunity because he has something to hide. It's ironic that he states he's going to refuse to testify because anything he says can be used against him (the fear being that he might end up in prison for breaking the law) can result in his being imprisoned for contempt for failing to testify before Congress.
Again, the actions of the Executive Branch officials are not necessarily improper. However, the repeated insistence that everything be covered up and kept from the other coequal branches of government, free from oversight, creates the appearance of impropriety. And that appearance weighs on the credit the People are willing to lend to the Government; and part of the reason why this Administration is thought of so poorly.