When lowering back to the ledge the climber needs to unclip a lot of the higher bolts as getting back to the ledge is a real rope stretcher. You also might find out that your 70M rope isn't 70M long as Jimbo and I did one day. We didn't tie into the belay end of the rope either. We tied a figure eight into the end and with some ropes the climber returned to the ledge as the knot wedged into the belay device.