Statistics are bordering on pointless in establishing the validity of the video and claim.
We know, full well and without any calculation the chances of such a shot are infinitely small, given that, the only reasonable action is ignoring it for the sake of tangible evidence.
For example, the skydiver was in a wingsuit, and the rock flies past him just as his parachute had opened. This means another person would have needed incredible timing to be able to match a rock throw/drop; having it go past him at a recordable distance while not hitting him.
I'm a skydiver so I've had my share of scares connected to parachute deployment, hanging around above something is for example a huge no. As the parachute opens, it's practically dead in the air; widening in area rapidly. Were someone to hang above him he is putting himself in real danger, his wingsuit is susceptible to changing winds and a few hundred meters (a reasonable estimate for how far you can expect a human to be able to aim a falling rock near another skydiver) go by in a flash.
There is also the practicality of holding onto a rock in a wingsuit (which you'd need to be able to follow his trajectory in the air). He could have devised a contraption on his stomach for the rock, and pulled it out at a proper distance, but a wingsuit diver pulls in with both arms in a quick motion in order to pull his 'chute, and would have to do the same for the rock, or suffer a nasty spin at a time he needs full control...
But reaching in still causes a dive, and loss of control, he loses forward momentum and falls rapidly, and he has to pull out a few pounds of rock in sync with the free hand in order to maintain direction, and now, in the midst of all this he has to be sure his rock does not hit his friends parachute and rip a hole, at an altitude I would be uncomfortable deploying my emergency 'chute, if he even notices the nasty tear in time!
There are actually more points to be made, but all in all, the film may have been doctored, but the jump itself most certainly was not an elaborate hoax.
We know, full well and without any calculation the chances of such a shot are infinitely small, given that, the only reasonable action is ignoring it for the sake of tangible evidence.
For example, the skydiver was in a wingsuit, and the rock flies past him just as his parachute had opened. This means another person would have needed incredible timing to be able to match a rock throw/drop; having it go past him at a recordable distance while not hitting him.
I'm a skydiver so I've had my share of scares connected to parachute deployment, hanging around above something is for example a huge no. As the parachute opens, it's practically dead in the air; widening in area rapidly. Were someone to hang above him he is putting himself in real danger, his wingsuit is susceptible to changing winds and a few hundred meters (a reasonable estimate for how far you can expect a human to be able to aim a falling rock near another skydiver) go by in a flash.
There is also the practicality of holding onto a rock in a wingsuit (which you'd need to be able to follow his trajectory in the air). He could have devised a contraption on his stomach for the rock, and pulled it out at a proper distance, but a wingsuit diver pulls in with both arms in a quick motion in order to pull his 'chute, and would have to do the same for the rock, or suffer a nasty spin at a time he needs full control...
But reaching in still causes a dive, and loss of control, he loses forward momentum and falls rapidly, and he has to pull out a few pounds of rock in sync with the free hand in order to maintain direction, and now, in the midst of all this he has to be sure his rock does not hit his friends parachute and rip a hole, at an altitude I would be uncomfortable deploying my emergency 'chute, if he even notices the nasty tear in time!
There are actually more points to be made, but all in all, the film may have been doctored, but the jump itself most certainly was not an elaborate hoax.