Saw this at a match a month ago. The shooter is standing in the box, the RO is standing to his left. At the beep both the shooter and the RO take a step forward. The RO steps on the corner of the box and the far corner raises up enough for the shooter to get his foot under it. The shooter is now lunging towards the ground on a very rocky surface. He hits the ground first with his knees and then with his hands. Luckily he didn't have time to draw so his gun was still in his holster.