As I understand it, answer is a subset of respond. You can respond to something and not actually have the answer. "we answer" means that the problem is solved, but "we respond" means that it's possible that their response didn't actually contain an answer. For all I know, they responded "I don't know".
In the audio clip, it sounds like the primary male voice is saying something lot more like "Ili demandas, kaj ge respondas.", (I don't know if ge is even a word), or even just "Ili demandas, kaj respondas." (Omitting the "we"), much more so than it sounds like the actual Esperanto sentence.
I reported it, as I have with a few others with the main male voice. Has anyone noticed that sometimes his annunciation is garbled or rammed together, and occasionally downright wrong in a place or two?