One accomplished person should not be belittling the accomplishments of another.
A good check to see if something is a joke is to see if you thought it was funny. To me it looks as if he wants to make this seem totally insignificant, and to increase his own stature by appearing to be above (pun intended) this all.
> I'll bet he would have a different opinion if it was him standing on that little ledge before stepping off.
I don't know. Most scientists I know have a tendency to put things back into perspective to highlight the really impressive stuff, so yeah, afterwards they would very probably say "Yeah and you may think that was high, but compared to a school globe, on scale it was only a millimeter. Isn't it amazing how stupefyingly BIG space is?!!", though that may make the Red Bull marketing team somewhat angry :P