Had a pretty high speed (35 mph?) sudden front flat in a right-hander at the end of a steepish descent. Grabbed a serious handful of rear brake and skated on the limit of control. Wound up about 3' on the wrong side of the centerline before I got the speed down enough to get back on my side. Luckily no one was coming. Stoker said she could hear the rim on the pavement. She stayed absolutely still. We stayed up. I'd mentally practiced grabbing the rear brake in that situation many times, so it was an easy reflex. Long ago, I'd had a lot of practice riding motorcycles at the limit. Maybe that helped, I don't know. We were lucky, I know that.