It's a little-known fact that the WTC had elevators which exploded upon impact! And that's what everybody heard on 9/11. They sound just like high explosives,
So there's no need to look for explosives, because there's no evidence for it.
Of course, if NIST happened to trip over it by chance, they would know their employer is a mass murderer. They would expose these monsters instantly, despite the massive implications of doing so. Those NIST guys are a fearless bunch, yes indeed!!
He definitely describes multiple explosions and being knocked back by one of the explosions.
So even though you think you know better and you think that is what everyone heard, i'll take the word of those who were there over some Internet debunkers who think they know better and suffering from some sort of cognitive dissonance.