I find this quite funny. I ought to be sympathetic, because I am one of those people who is much better at debating a point in writing than I am when speaking. I can get flustered and confused when talking.
Having said that, in a situation such as a podcast interview, where I am familiar with the subject to the extent that I'd written a book about it, I would do pretty well. Maybe not as well as I'd do in writing, but I would certainly hold my own. Why? Well, first, because I'd have thought through all the arguments several times before arriving at my position, and secondly because I'd have made sure to prepare for the interview.
What strikes me about DFW is that she was put in the same situation as all the witnesses in cases such as the Allison Bailey or Roz Adams or Rachel Meade tribunals, where they seemed absolutely stunned to be asked perfectly ordinary questions about their beliefs. Because they'd spent years in an echo chamber, refusing to debate with anyone who disagreed with them, they had no answer at all when challenged to explain what they thought. They couldn't cope at all with someone saying, for example, "That contradicts your last answer" or "Can you explain the logic behind this apparently illogical belief?"
And so DFW just wasn't prepared for it. When asked to explain herself, she couldn't, because, let's face it, gender ideology is completely incoherent and nonsensical, and no one arrives at it through a process of reason, they arrive at it simply because it is fashionable, and going along with the crowd is easier than challenging it.