Play this at .25 speed; you can see it better.
Notice how 81 fell completely out of bound, giving the CB a clear path to the ball.
I see QBs almost always throw this ball.
The only way a receiver leans outside of the playing field is when the ball gets thrown a bit too far outside.
If only 81 had stood up straight right next to the sideline, I'd say the ball would still be to this outside, right at the edge of the field.
The CB would have to go through him to get to the ball.
There's another angle that isn't shown here.