I quite agree KS. It would indeed be a wonderful thing if the truth about any subject could be used to end an argument. Our experiences in life warp our view of truth though. A fact doesn't change, but our view or understanding of it does. When they worked out that the earth was not the center of the universe, it didn't suddenly not become the center if the universe, our greater understanding of it meant we now saw it in the right place.
I have seen people be proved completely wrong but still defend their defenseless position because they didn't want to give in and be seen to 'lose' to someone they perceived as cocky.
I know some people that will look at this video and may lean toward being swayed but as soon as they hear those final words, the wall will go up. For them those final words will negate everything that came before them, no matter how sound it was.
It is an excellent video, I just think from a tactical point of view, the warm appeal to reason will jar to a halt for some people, like a needle being bumped off a record player, on hearing his closing statement.