You may be right, I would have thought a microwave sized boulder is there that never used to be, the other member of my party with me said it's a shame it wasn't so accessible to all. Easily poppable. Sounds like I pretty much got to the bottom, but being alone I didn't want to go much further than the pitch with the ramp hauling set up. Impressive engineering by you and the crew and that cascade is definitely worth a view to anyone visiting owl holes. I may return for further inspection, probably in the summer.
Mike.