No matter how many emails Clinton discloses, if this imagined missive fails to materialize, it will always be thought of something that's being hidden, as opposed to something that does not exist. The only solution is for none of this to have happened in the first place -- and it's not as if this required some super-genius amount of foresight to prevent. Rather than solve the problem, it must simply be endured -- and not just by Clinton herself. Whatever you think of this email micro-event -- be it the intimation of a larger disorder, or one more shiny object of diminishing value -- the fact is that it has altered the "invisible primary" in some measurable way for Clinton's allies, her opponents, and the media tasked with covering the story.
Manipulative tactics -- such as carefully editing both the call and response of a protestor and the crowd -- cannot simply be attributed to 'bad judgment' or even 'bad journalism.' They are, at their most basic, deliberate efforts to knowingly foist a defective product on the public, without regard to the harm it does.