HEHEHEHEHe...eh...
I really have grown to hate the word "interesting", so I'll say informative...but even that isn't a complete sentiment.
We live in an extremely individualistic society.
Based on our cultural premise, "better them than me", I can understand the reactions of the majority of white people in the experiment.
The painful reality is that, in this individualistic society, we are black, and dominance is wielded by whites.
White american culture, from my experience, seems to teach one to agree with whatever the present status quo is. Which is my understanding of the white guy's duplicitous reaction. At best, he is trying to be accommodating.
I might be slightly bitter, and this last statement may be a reflection of that, but I feel that the mob of people that left in the last shown scenario, may have only left because it seemed like a cool thing to do. After all, they all had plenty of time to react to the act staged for them.
I can say without fear of being naive, that the human reaction should have been to step in. Even with black nationalist political beliefs, center or right, I would have stepped in if a white person was going through that. Even if just to frame the quality of the store I was about to spend money in.
Ultimately, I would say that is the question. As an American Black who has been stopped appropriately, (fun times in childhood...), and other times without reason, my reaction in a pluralistic society seems to naturally be to step in for an American Black woman. But what if it was a white person about to be jumped for just being white? And YOU had the power to stop it....