Yes Lookleft, that's my impression of the risk assessment too.
So the risk assessment included historical data or research of the performance of a UAS after struck by fireworks that indicated it would crash straight down?
Maybe it did. Like I said, I'd love to read the risk assessment on this one.
Drones could do anything when hit by fireworks... It's electronics after all and a knock could upset the gyros and it could spear off in any direction and into anyone. All the failsafes in the world may not stop it... Refer to ATSB report for loss of control of a UAV at the Melbourne MCG.
But, are they safer than a single engined Squirrel overhead at night? Probably.