Don't know whose downvoting you, nuclear reactions, whether fission or fusion, produce very considerable amounts of light, much more than any conventional explosives would.
Not to mention, the depth of field that videographer was maybe a mile or so from the POI. Even on a very small nuke, the overpressurization would've probably blown him over. And like someone said below, the color was very orange, indicating a chemical explosive.
Don't know whose downvoting you, nuclear reactions, whether fission or fusion, produce very considerable amounts of light, much more than any conventional explosives would.
The color of the light will help tell chemical signature.
Not to mention, the depth of field that videographer was maybe a mile or so from the POI. Even on a very small nuke, the overpressurization would've probably blown him over. And like someone said below, the color was very orange, indicating a chemical explosive.