Good grief - it’s an artifact caused by internal flare within the camera lens or anti-glare surface coating on the objective surface . Notice how the shape of the mysterious specter of doom is exactly the same as the brightest area of the flames and as the camera pans the artifact movement is exactly the same as the camera, right down to the bit of hesitation when the photographer begins the pan. You didn’t need to talk to a retired pastor, you needed to talk to a photographer. Mystery solved...
You nailed it.
probably a reflection of the fire of the truck on the inside lens of the camera or filter.
as the cameras axis is closer to perpendicular to the fire, the image trails off because there are fewer lens elements to reflect the fire.
good call.