At that point in the image, he is getting back up to celebrate. At the point he hit the ground, his arm is still under the ball. Even if the point of the ball hit the ground. Right before that cap, you'll see this:
This angle they used is somewhat biased in that you can't see that his arm and hand are under the ball the whole time until the image you show when he's in the process of standing up. I still don't think there was enough evidence to overturn the call on the field.