And remember, for the unifilter he kept the airbox unifilter gasket. That closed the airbox tight.
With the paper filter test, air could go through the filter AND the gap between the airbox and airbox lid. I think this becomes and apples and guacomole test.
The unifilter gasket should be there on box scenarios.
But the real issue here is that if you lose 2 ponies now, with a better filter, at least in the long run you are not letting other ponies out of your engine by keeping it dust proof... :-)