I'm not so sure about Barriss being behind the actual bombing myself. Clearly there is another on that's going to go off while Letta is being held since we have no scene the funeral picture. I like this theory best actually. Barriss was quick to start killing Clones in Brain Invaders. If Letta attacked her/them she might do the same. I can see Ahsoka taking the fall for her. That just sounds like something TCW would do to me. Barriss being hind everything or part of the conspiracy would be a hell of a twist. Its interesting she seems to agree in the clip.