Hopefully the contrast between the others’ unthinking ‘nice’ answers and David TC Davies MP 
would have got a few of the audience spider-sense tingling that there could be more to this question.
I can well believe he gave answers on Brexit that I would deeply oppose but I am grateful to him for being actively gender critical in Parliament which no other MP has been. We know there are many who in private will be gender critical but are too cowed by the pressure from the trans lobby to feel they can speak up, which is how come we are still in this mess with women and children’s rights coming last in the queue.
If we all give the BBC our Answers on this they will find it harder to ignore it.
I don’t quite get what BBC thought would happen though with this question: would they expect the panel to congratulate a famous out gay male celebrity (not always an easy thing to be) ‘coming out’ again as non binary? Saying ‘I’ am changing my pronouns, when actually it’s about requiring others to use different pronouns on threat of ‘misgendering.’
I don’t think non binary has got any public traction at all, people are typically confused then eye roll or just smile and nod at the whole idea of adopting a newly invented category. Especially because this requires awkward ungrammatical language to retain any sense of linguistic logic.
That dissonance then gets some people thinking that 500 different flavours of gender can’t be taken seriously.
I notice that the TRA party line is very much: being non binary is totally different to being transgender,
Eg in quoted the Independent: ‘Stonewall explains that gender identity - a person's own sense of gender - is not the same as gender expression, which is how they express themselves. It is also not the same as being transgender, which refers to a person whose gender is not the same as, or does not sit comfortably with, the sex they were assigned at birth, according to Stonewall.’
(See also from US National Centre for Transgender Equality-
‘Non-Binary Defined:*
Most people – including most transgender people – are either male or female. But some people don't neatly fit into the categories of "man" or "woman," or “male” or “female.” For example, some people have a gender that blends elements of being a man or a woman, or a gender that is different than either male or female. Some people don't identify with any gender. Some people's gender changes over time.
People whose gender is not male or female use many different terms to describe themselves, with non-binary being one of the most common.’
transequality.org/issues/resources/understanding-non-binary-people-how-to-be-respectful-and-supportive)
(I’d say ‘all people’ are either biologically male or female but then I’d talking about actual sex categories.. 
)
I think the messaging about this gets quite awkward for TRAs because it shows how transgender dogma is about thinking inside the rigid gender box while NB is actually a bit like the start of being gender critical (‘let’s have no gender boxes!’) by saying, ‘I don’t fit in these boxes’.
(Whereas GC people would then go on to say, ‘sex is real and unchangeable for everyone, the gender boxes have always been fake, a trap set to give all the power to those at the top of the patriarchy tree..’)
The obvious difference between non binary and GC belief is that NB also looks to be sex-sceptical (NB believing that biological sex categories are not binary, which is just scientifically untrue, and instead believing sex exists on a spectrum..? I’m struggling to write this because it’s hard to follow the concepts. Hope someone will correct me if that’s wrong. )
And at this point a lot of people feel uncomfortable that getting on board with non binary would require them to adopt magical thinking: that the biological binary of sex, common to all living creatures that sexually reproduce, doesn’t exist as a stable category.. and that individuals who declare themselves NB have simply spotted this ‘fact’ and are bravely ‘owning it’ or being ‘truthful’.
Except all that goes too far against most peoples’ own experience of living in a sexed body, and our knowledge of how babies need to be made, so that’s where a lot of people go 
Sam Sam says he floats between being Male and Female.
Explaining what the terms meant to them, Smith told Ms Jamil: "Non-binary, gender queer is that you do not identify in a gender."
"You are just you. You are a mixture of all different things. You're your own special creation. That's how I take it. I'm not male or female, I think I float somewhere in between. It's all on a spectrum."
inews.co.uk/culture/music/sam-smith-non-binary-gender-explained-593406?amp
For the first two sentences of his quote above- ‘You are just you. You are a mixture of all different things.‘ I was totally with him before he went down his own specialness rabbit hole and conflated sex with gender.
I do think that NB beliefs might easily become GC beliefs if people just keep on actually thinking about it.. sex and gender clearly not being the same thing.
www.standard.co.uk/showbiz/celebrity-news/sam-smith-says-life-is-good-everything-is-in-its-right-place-after-changing-pronouns-to-they-a4242221.html?amp
I also think that although Sam Smith has got an initial welcome for adding visibility for NB people (see BBC link below, vox-popping people at the recent Trans Pride in London) because Smith says he won’t talk about his NBness until he is ready to be eloquent about it... once he does talk, (if he ever does, #nodebate culture being what it is..) it will quickly be apparent that the politics or beliefs of it don’t stack up against reality- then at that point he’ll be criticised by the TRA lobby for not doing NB representation ‘properly’ or something, or just for being a ‘trender’ and ‘not really even being NB’.
The TRA dogma would hate it if anyone inadvertently held up a mirror that would make it appear that the TRA lobby are trying to cement people into rigid gender roles via medicalisation, at great physical cost and at a too-young-to-decide age, or while they in a vulnerable state looking for any way out of emotional distress at gender stereotyping and/or body dysmorphia, or because they are misled to believe they can change sex, or because they are sexually motivated by the idea of ‘being’ the opposite sex. And people will notice they don’t advocate for just dressing however you want or more importantly advocate for talking therapies and emotional support for distress, he emphasis is much more on rushing to medicalise.
www.bbc.co.uk/news/entertainment-arts-49688123
Sorry about the massive post