Similar in friction concept to an ATC, its the brake hand bending the rope around the device that will hold the climber. If she were to have fallen, I'm sure the rope would have no problem sliding right thru without a hand holding it down. Sketchy. I'm not certain how, but certainly lucky, not to have seen anyone seriously hurt themselves or others climbing in korea.
Oh, the delicate peregrinations of those ten sensitive fingers, scuttling across the rocks in desperate Braille. - Sid Marty