There's a reason it's clipped & framed like this. It's fake/staged for a show or movie.
If you go and find the uncompressed video version of this from like 4 months ago, you'll see the crowd just below the balcony. And they're all casually chatting. the masked guy is shouting some demands, can't really hear him very well. And then when you hear the airsoft pop.
And then you hear the polite applause from the crowd that's right there.
Then think about it rationally- while they're repelling down and getting into position... what happens if that guy with the gun looks up. Not even straight up, just glances up?
They're exposed and likely dead.