There's a difference between the attorney's obligation not to disclose privileged information and the attorney's right to express opinions that are unrelated to his prior employment, but involve the same client. Saying, “he told me he perjured himself” is a violation. Saying, “the guy ran over my foot yesterday” isn't.
All Craig is doing is using his skills as an advocate to make arguments based on the same information that's available to the rest of us. He's doing it persuasively, which is why the Hillary camp wants to shut him up, but what he's doing is perfectly permissible.
And just how does one comparmentalize all that information to make he doesn't mix in some privileged information along with non-priveleged information?