user wrote: He's lucky his expensive drone didn't get blasted out of the sky.
I don't think he was taking TOO much of a chance. I think that such lightweight drones probably could take anything short of a direct hit from the initial exploding fireworks shell, and he kept his drone outside of that zone (well, most of time). While secondary fireworks explosions look dramatic they get nearly all their momentum from that initial explosion.
While this video did not show this (at least not in any of the parts that got on YouTube), the biggest problem I see would be if a drone pilot flew his drone far UNDER the explosion zone of the fireworks because a yet-to-explode fireworks shell might get deflected in an unexpected and possibly dangerous direction.