It's interesting how the mike in the humvee failed to pick up the sound of the impact/explosion.. it was loud, very VERY loud.. even from our vantage point approx. mid-point on the 12000ft runway.
Mungo P, from your knowledge of the perimeter road, how far do you think the camera was from the crash?
It looks like there was a small hill or it crashed in a ditch, so this would have also reduced the sound wave, also you were downwind?
The camera was upwind and (probably) in a sealed car (sound of the horn is faint as is truck passing by..)
Also Mics on cheap cameras are notoriously crap and in this case the auto level control pulled down the "noise" level so as it rose it was pulled down (too far) and muffled.
Unlike similar views from Humvees in Afghanistan this explosion (a deflagration rather than a detonation) did not have a shockwave travelling faster than the speed of sound.
I agree that it was bazaar that the person filming did not even gasp???
Sounded like a Brit(?) on an airport perimeter road in Afghanistan, it may be that he was dog handler in a security role, trained and "switched-on" to keep his utterances under control, good control of voice commands is a pre requisite for dog handlers.
Interesting that his dog apparently needed calming down yet he was pretty cool, perhaps the kind of reaction a parent would have if a child was the car?
He stopped and had the car in reverse before it had hit.