@domgreves@CRCuthbert@B_Strawbridge I can answer this - that dark cone shape is the shadow of the hill I was stood on, caused by the sun behind me. It also explains why the rainbow stops at this point as the sunlight is not reflecting off the water particles that are in shadow. Hope that clears things up!
The real unanswered question for #FreeSoloLive should be why did @AlexHonnold remove the fridge door? I was on the edge of my seat awaiting the conclusion