The video just shows that Bob was able to maintain the g-forces in z-direction of the airplane. It does not show or demonstrate the absolute value of the g-forces. If you look close enough, you will see that he began the rolls while in climb.
EDIT: The latter serves as proof enough that a barrel roll is NOT a 1-g-throughout manoeuvre. (You cannot initiate a climb from level flight without pulling more than one g.) Since Tex stated such in his interview, most pilots believe the one-g-barrel-roll must be true. Well, physics is optional for a pilot...
Last edited by TripleBravo; 19th May 2012 at 18:41.