Perhaps not that hard. It seems the VCDL have their own tape, so they can document that the 9 seconds of silence that were presented as their inability to respond to a question actually came about because the producers instructed them to sit silent for ten seconds so they could "calibrate the equipment." Then,, by massive feats of legerdemain, those ten seconds of "calibration" somehow got edited into the sequence following a key question.
Curiously, their immediate responses to the question (which they also have on tape) did NOT make it into the finished piece.