I'm not sure I buy that. If Cheney,turned, fired, noticed (too late) the guy's head peeking over a bush and then saw his head disappear in a downward motion, would he not say "I saw him fall".?
Outside of our right to better jokes, with which I agree, what could Cheney have possibly done (wild speculation allowed) during the course of a hunting accident that would be deemed as something which impacted his role as VP? Why hide anything?
Even if he was smashed drunk, dressed in a tutu and singing show tunes why not just spill the beans? Well ok, maybe not about the show tunes but really?
Outside of shooting the guy on purpose, what could he have possibly done wrong that would truly matter?