I understand, in this case the drone had permission to be where it was, but I've never been clear on the limitations.
I thought that generally we could expect privacy and control of the space about one's property up to 500'. A/C are forbidden from flying below 500' except with special authorization (t/o and landings excepted of course). (Remember Barbar Streisands lawsuit to prevent aerial pictures of her property? Judge said above 500', to bad.)
I thought drones weren't authorize to fly any higher than 400'. Therefore, without permission, a drone could never fly over someone's private property.
On the other hand, destroying someone's property, even if they're in the wrong is frowned upon.
On the remaining hand, to disobey do-not-discharge-firearms one would need a clear and present threat to life or limb.
In my state and county, air guns are not considered firearms. If I was going after a drone, I develop an air powered cannon with a net.