As far as the original question is concerned, it is so clear that he or others simply can have a look for themselves. If it was blocked because something visible in the dark patch was so big that we would see it, then they can easily see it themselves. If I was hiding something, I would only block the little bit of light for that star, not a massive section that would provoke suspicion! They must think that the US government are idiots of the lowest order – rather than idiots of a high order!!! Pardon my humor.

Even Carl Sagan’s movie “Contact” (haven’t read the book) contains astronomical fallacies. In particular there is a plot point turning on whether gazillionaire John Hurt might have faked the alien signal. But the signal persisted over many months – and was stationary in the sky. Its parallax must have been sub-arcsecond, else Jodie Foster would have trivially known it was local. Its distance was thus known to be more than a parsec (> 3 lightyears). If Hurt had technology to spoof the signal from lightyears away it would have been a bigger story than aliens.