Hindenburg jokes aside, how do you ensure safety? Even if you only inspect infrastructure away from human habitation, there's still the risk of forest fires and such if there is an accident.
I don't think they're as dangerous as people think. If they ignite they go up in a whoosh, not a bang. The only debris is your payload, now falling. So as as your payload is not also made out of flammable material (as was the case with the Hindenburg) then I don't think it's any more of a fire threat than having power lines near trees is in the first place. Up is conveniently the right direction for a ball of flame.
Of course all of this goes out the window if you let it become entangled in a tree...
Do you have any video that you could share about the lighting on fire of the balloon?
We lost contact with the payload almost immediately and never recovered it, but lost enthusiasm to try a second time.
We had bought two balloons just in case we needed a second. Waited for a rainy day and took the second one camping. I wish I had grabbed a video, but some among us were overly paranoid about creating evidence.
It was just a big blue orb and a whooshing sound. Presumably there were some flaming bits of rubber involved but we weren't able to recover them (we made the tether too long, out of fear for it being more dramatic than it was, that it was hard to get a good idea of what specifically went on).
Has there ever been a burning man effigy with a lighter-than-air component? That would be a good venue for exploring the dynamics of baloon fires (it could tethered such it wasn't above anybody when it went up).
(Aluminum powder is used in propellant, it was used to coat the Hindenburg, therefore the Hindenburg was coated in rocket propellant.)