Consider a property line not just a line on the ground, but an invisible wall extending from that line on the ground up toward the sky. That's the issue here, is that the hunters are disturbing the 'air rights' of the adjacent properties by crossing that invisible wall, and not just by stepping physically onto the property. Using a helicopter wouldn't be much of a loophole if the air rights are concerned, I think.
Edit: after comments, yes, duh, it doesn’t extend infinitely and there’s the aspect of reasonable use, c’mon, why do people need their hand held through everything. Flying a helicopter over another property at 100’ is different than 2000’. Talk to the FAA.