The 70 knot call was 7 seconds before hitting the fence and going off the cliff. He was reducing reverse before the 70 knot call so must have thought all was well at that time. Why at 70 knots couldn't he stop in that 7 seconds or go back to max reverse thrust if rubber deposits reduced his braking? I know nothing except what I have learned here on Airbus 320 logic but it seems he lost all braking shortly after that call of 70 knots. I landed on that runway many times and always made sure I could turn off on the taxiway 1000 ft short of the end before I would relax reverse and braking. I said it before but that last 1000 feet should be for emergency stopping only. Once slowed down to a safe speed use it to save brake wear and temp. He was in manual braking then so autobrakes would not be the problem at that time.