I think there are a hundred different theories on Tunguska.
It's the Teton event and that long 1,500km trajectory in the atmosphere that stuns me.
In no part of the super-8 footage does it look to break apart. Every other body I've seen move that hot and that fast has. Add to that the resonant return it was supposed to make, and it makes me think of a von Neumann probe doing a Leonov type aerobrake a la 2010.