On what theory? First, it would probably be deemed a trespass by them justifying her right to shoot it down. Second, even if she were found liable in a civil suit, the damages would be limited to the value of the destroyed drone - a couple of hundred bucks at most.
“On what theory? “
The fact that she clearly said she wasn’t sure why it ended up where it did, didn’t bother to figure it out, and then proceeded to destroy their drone after it hovered for a grand total of a second. Her whole story seemed to read like she was just waiting for any reason to fire her shotgun at it. She comes across as a nut.
Calling it “trespassing” is like calling a kid whose football accidentally went over the fence, and some yahoo next door shooting the football the moment they saw it, trespassing.
Give these guys a minute to correct for anything that might have gone wrong before you just willfully destroy stuff that doesn’t belong to you.