I think and this is just common sense reasoning that a rc plane gets
into the UAV arena when it is flown at a location or altitude that can
conflict with full scale planes.

I would also say when the plane is overflying a area that is not normally
set aside for model use. as far as haveing a camera onboard or being
paid to fly or haveing a auto pilot on board I dont see what that has to
do with anything.