@DrewDad,
If the advice of counsel defense was applicable only when that advice was correct, it wouldn't be much of a defense.
Follow your counsel's correct advice and you won't break any laws and therefore not need any defenses.
It is precisely when counsel's advice may be wrong that the defense comes into play.
The argument that is being made against the Bush Administration's use of the Advice of Counsel defense is not that the advice was wrong (although those making the argument certainly think it was), but that it was fraudulently obtained; that the process the White House lawyers went through to arrive at their opinions was rigged by Bush/Cheney to obtain a pre-determined opinion that the actions they intended to take all along were legal.
Advice of Counsel will not operate if the matter is not of sufficient complexity to require the expert opinion of a professional attorney, nor if the defendant clearly knew or should have known the advice was wrong.
If your attorney renders an opinion for you that it is legal to kill your wife, after you do the deed and are charged with murder you are not going to be allowed to maintain a defense of Advice of Counsel.
It may be that the rendering of the "torture opinions" was a legal sham and that Bush/Cheney believed all along that the methods they sought to use were illegal, but unless or until that is proven the Advice of Counsel defense should, if needed, serve them well.
I doubt anyone believes that our legal system should be driven by the opinion of a mob.
Because there are tens of thousands of Americans who believe Bush/Cheney are guilty of having broken one or more of our laws doesn't mean we need or should launch an investigation and prosecution.
There are plenty of facts available to the Justice Department upon which they can reach a determination of whether or not Bush and/or Cheney should be charged. If they believe they need to investigate further, they can, however charges should only be brought if there is a reasonable chance that the prosecution may be successful. Federal attorneys can't go before a DC Grand Jury and hope to secure an indictment simply because a lot of the political opponents of Bush and Cheney want to believe they committed crimes.
If the professionals at the Justice Department truly believe that members of the prior administration are guilty of crimes and that there is a reasonable chance to prove that belief they should move forward.
What we do not need is the sort of political witch hunt that takes place from time to time in DC. Millions of dollars are spent, lives and careers are ruined, and in the end we are generally left with the only crimes being prosecuted involving perjury or obstruction of justice; entirely dependent upon the process of the witch hunt itself. This is not self-cleansing, it is self-mutilation.