But it is a violation. I guess from my perspective it was a justified violation of the rule, but it was still a violation

Depends on the meaning of rule and violation I guess. I interpreted it as a sign posted at the entrance of the park. I interpreted violation as something that would be stopped by the park rangers.

Their point is that "was the rule violated" is a combination of "is a vehicle" and "in the park", hence both axes are relevant factors. If pushed, I would concede that the ISS is a vehicle, but I would consider the bounds of the park to end far lower than where the ISS orbits, so despite being "a vehicle" it doesn't violate the rule because I don't consider it "in the park". "Is it in the park" isn't relevant for most of the questions, but it's still an important part of the premise.