Adam One's drawing is an elegant explaination of the theory that the Park Bench designers thought was true. I think, in fact, the design was not good because - short of airflow separation - the freestanding ailerons were not as effective as conventional ones, which affect pressure distributions on the much larger areas of the wing itself.
At least the freestanding ailerons below the wing make more sense than the ones above it.
A good example of how a rear surface effects the flow far forward is the aerodynamics of tailgates on pickup trucks. Most people think removing their tailgate will lower the vehicle's total drag but usually this will increase it. Another good example is how a rear spoiler can actually affect radiator flow at the vehicle's front - something I have witnessed in the wind tunnel.
Allan