FLAT EARTH Eclipse 2017 100% DEBUNKED [Must Watch]

How do you explain that https://eclipse.gsfc.nasa.gov/solar.html still reflects that all calculations are by Fred Espenak and that he assumes full responsibility for their accuracy? As Dr. Zack states in the video, what does Fred know that others at NASA do not? Or stated differently, why isn't there a standardized mathematical model at NASA which would allow ANYONE to accurately predict solar eclipses? If we are to believe NASA, they know with certainty sizes, distances, locations and movements, etc. So why is it that Dr. Zack, using these same inputs, does not arrive at the same result as Fred Espenak?
This has been a really hot topic as of late and I think this video is another nail in the coffin of the phony heliocentric mode