But what if it's a single unit (no warhead) which only works via kinetic contact, then perhaps not a vehicle.
Trust me, if there weren't any laws, people would be shooting down airplanes above their farms, or at the very least, writing a lot of angry letters to the FAA. The laws that we have right now allowing the freedom of air travel were hard-won and unpopular among those affected.
Therefore, the park in this exercise would mostly like try and shoot down the International Space Station, or else risk the reputation of not being strict against surfers carrying surfboards. It's exactly the same thing.
So where do you draw the line?
Similarly a subway train passing underneath the park is not "in" the park, nor are vehicles that are at the antipode of the park on the polar opposite side of the Earth.
To me, that doesn't change the answers much. You still have to have some definition of vehicle that inevitably assumes some context.
That to me means any human-propelled thing smaller than say a motorbike is not a vehicle.
So I only said 'is indisputably a vehicle' to cars and similar (even if was an ambulance or police car)
But you were specifically instructed to not use any laws local to your jurisdiction, and that's why this can happen. The 15 countries it flew over are members of the ICAO, which delegated some of their sovereignty to the common good of easy air travel. It could have easily worked out some other way; fly over our country without stopping for immigration, and we blow up your plane. (You can see this in action if you fly your plane from Canada to do a low approach over the White House. You probably won't be home for dinner.) Similarly, in the US, the FAA decides who can fly over your property and how low. These are not universal constraints on existence, just actual laws that people wrote down because nobody could agree on the details. I'd venture a guess that if you asked the average property owner if airplanes could fly over their property and stare at them in their hot tubs, they'd say "no". However, the law simply doesn't agree with them, and a satellite is photographing your underwear as we speak!