This is awesome. Can't get much more entertaining than this live clip.
This version shows Bart Sibrel following Aldrin and pestering him, until the former astronaut explodes. The right cross from Aldrin comes at the 1:20 mark.
I was fortunate to have a beer with Buzz Aldrin at a wedding in 1992. There is no doubt that he walked on the moon. Mythbusters offers proof below.