That really wasn't at all a scientific test. One gut punch by two people is not a good comparison.
I don't know why people get so offended when people assert that guys are stronger than girls. Biologically, guys DO tend to be stronger than girls due to things like hormones. It's just the way things work and there's no need to be upset about it. It doesn't mean that every guy is stronger than every girl either, obviously (the basement-dwelling nerdy guy is going to be weaker than an MMA fighter woman).
This isn't meant to diminish women in any way. We are just different from one another. We have our own strengths and weaknesses and that's ok.
I found the following Mythbusters episode to be a far better comparison between men and women. It is by no means perfect, but still better than the first clip. In the show, they compared different people of different age groups and tested them in more than one way.