My initial feeling was that it was a completion and he was down as soon as he hit the ground.
But after some more thought, I’m going to go with INT.
If he didn’t establish control of the ball before it popped out when he hit the ground, then it’s a live ball.
Without established control, whether he hits the ground or not is a moot point.
As long as the ball hasn’t touched the ground, then it’s a live ball.
That’s my final answer, Regis.