This may hold water except we know that most of the answers were standard extremist answers
Which is of course why a film with this title was made in the first place! He knew it would be laughably easy to just point cameras at these people at try to get them to explain themselves. The incoherence long pre-dates this exposé.
it is not like Walsh had to scour the world over for these people. Some of them are lecturing in universities, some are clinicians.
If he didn’t approach these people, he would have got similar answers approaching many others.
He spoke about his surprise about how far that went in his recent interview with Jordan Peterson:
What was actually a surprise to me is when we went to all these different cities and we went out on the street and we did man-on-the-street interviews, just talking to regular people about these issues, and asking them if they can define the word woman, and all this.
And I really thought going into it that we would be able to predict before we talk to somebody what kind of answer they're going to get and I thought that we would talk to a lot of confused younger, you know, gen-Z types and we get the typical stuff from them but then if we pulled aside some older guy, you know, with his wife, and they're walking down and we start talking to them, but I thought we would get just plain common sense and we didn't. We found that the vast majority of people we talk to, no matter their demographics, they were they were basically saying the same kinds of things that we heard from the college professors, only they didn't know that that's where they got it from. So they didn't even know - it was clear to me that they didn't know exactly what they were saying, or why they were saying it, but they had a party line that they were repeating.
(Peterson had a fair bit to say about that, as on most things, but I'll skip it here.)
A bit later, after talking about the totally different responses from Kenya:
I think that back in the United States there was some confusion about being put on the spot to explain something that so innately understood. But then there was also what seemed to me to be an awareness among many of these people that this is a loaded question now, and they can't really talk about it and be honest. In fact we heard about that - there are many people we talked to who aren't in the film because they didn't want to be on camera. They refused to be on camera and they would tell us, like, I can't talk about this with a camera rolling because my job, because I'm going to school, because this and that.
So there's a real there's a real fear that people have that pervades through this whole conversation, and I like to think that over the last year some of that fear has dissipated - a little bit, not completely, but it just seems to me that normal people are more open about just saying what's clearly true when it comes to issues surrounding gender.
But at the time when we made the film it was it was just everywhere, and it was really difficult to get anybody to want to have this conversation at all.