Sounds right to me...I thought that when a lifter on the lobe is in the valve closed position the check is in a position to allow oil into the bottom compression chamber. The compression chamber is sealed when the lobe comes around and begins to lift the lifter...pushing the ball back onto it's seat and retaining pressure in the chamber. Normal leak down comes from the pressure chamber back to the reservoir between the plunger and internal lifter body bore. If my understanding is correct, I would assume they should leak down with the engine off.
