This is a two pitch route, if you haven't done it, get on it, it is one of the best routes in the country; I almost fell off laughing). The mid height belay is formed by a constricted stance (when you have 3 people) on top of a chock stone at the front of a cave. I led the first pitch and being out of slings built the 3-point anchor with the ropes. In order to make the stance more readable (which given what happen is somewhat comic) and easier, when the second (Pete) arrived I rebuilt the belay using slings he had cleaned to facilitate tying 3 climbers into a powerpoint and swapping ends of the rope so Pete could lead the final pitch. The third arrived and clipped into the powerpoint. The stance is constricted, the cave and powerpoint dark, the light from month of the cave bright. Pete is tied in with a rope, I'm tied in with both ropes, the third is tied in with one rope. Pete went to clip directly into the powerpoint with a daisy (PAS-style). This was difficult for him as the powerpoint was below him and out of sight, it was also under a mess of other ropes tying us in, or going from me to the anchor pieces. Given this difficultly I grabbed the PAS and clipped Pete into the powerpoint. A while later Pete found his PAS was not clipped to the power point, yet its twist lock carabiner was. And hence he was probably not tied to the cliff (assuming at this point he had untied his first attachment point, I can't remember). Falling off the chockstone would be fatal.