That part of the building may have just barely survived the explosion and been covered with grain (or whatever was in the silos). It is possible the silos didn't spill for long enough for him to escape ... maybe.
Also, a huge amount of the building damage was done by fire over the following hours. So maybe the guy lived long enough to get away from there.
Or maybe MechAg94 was right and he was livestreaming his last seconds, although the fact that just before the video cuts out you can hear someone speaking is probably a good sign.
It was a person. They walk around and at one point you can even see their shadow.
I'm still finding it to be problematic as hell. The concussion from an explosion that big, even with partial shielding, should have been more than enough to either cause significant trauma even if it didn't cause immediate death.
A blast powerful enough to crumble reinforced silos like that?
Sorry, but I'm just not buying it. Maybe by some miracle, but until I see something proving it, I'm EXTREMELY dubious.
Oh, and regarding fire, the after pictures don't indicate much in the way of fire damage to the silos, nor do the before pictures indicate much in the way of fuel to be burned in the surrounding area.