All the sources (1) agree that everybody was kung fu fighting. In addition, no verifiable source mentions that nobody was kung fu fighting. In conclusion, we can assume that everybody was actually kung fu fighting. [I have a PhD in physical anthropology]
Not sure if this is sarcasm or a reference I'm not getting, but just in case: It's not AI generated. I know this because the sign in the background is legible. The hand belongs to the woman to his right. The photo was taken right as he was lifting his hand to adjust/remove his sunglasses.
Let's say for a minute, that hypothetically, everyone was in fact kung fu fighting. Now statistically speaking of course, this is impossible. Now hypothetically if they were, hypothetically of course. Now, would they all be performing the same so called Kung Fu move? Statistically speaking that is highly unlikely. This would also, hypothetically, be quite dangerous if it were to actually occur. Coming from a medical official, my wife, who is a doctor, she says that hypothetically, this would be dangerous. So, logically, this would not happen. So in fact, there is no way, impossible even, that everybody was Kung Fu Fighting.
It really depends on what group of people we're talking about, what if you were attending a kung-fu-con, then the odds of everybody kung fu fighting increases dramatically