The parents are interviewed, and from my experience there might not be quite as much more to the story than it may seem.
Children are capable of absolutely amazing things when they are told "yes" and given respect and minimum guidance. Of course my example is not as mind-blowing as this, but my son built his own forge and has made beautiful knives and swords from found metal. Tons of research and sweat and persistence on his part, and not ours. And if we were interviewed about it, the soundbites would come out about the same: "Yup, he did it, we were a bit worried, but he was managing the risks and knew and followed the necessary rules, so ultimately we trusted him."
Sure, but the question I'd have for you as parents would be - ok, but how come you you have a forge in your house? Is that your profession? Hobby? Did you build it specifically for your son? What did that involve? How does your son know how to operate a forge in the first place?
Like, that's just few questions that come to my mind in like 2 seconds, I'm sure a competent interviewer could think of more.
1. I didn't have a forge in my house. As I said, he made one, using found materials and a few cheap tools he bought with his own limited money, outside.
2. I am a software developer, I have done a bit of small vegetable farming, and my metalworking experience is limited to watching the blacksmith at the historical museum.
3. My son built it specifically for my son.
4. Building it involved his working his butt off hauling discarded materials like cinder blocks from the neighborhood.
5. He studied very hard on many aspects of the craft, for months, online.
My input into this was computer access, permission to proceed, "no you can't put it there", (then after he set it up in an approved spot) "neighbor says you have to move it further away from his yard", and buying the fuel since he's not old enough. Then one day dropping my jaw when he walks in the house with a beautiful knife.