The qb has to have control of the ball when the arm is moving forward to make it a pass. The ball moving forward doesn't make it a pass. Instead it is a fumble that is moving forward because the qb did not have possession. If it goes into the end zone it is a touchback. it is no different than is a runner fumbles the ball forward. into the end zone.
Think of it like this: qb takes the snap and throws the ball up in the air and bats it with his hand. Ball hits the ground moving forward. That is a fumble.
I think the call was correct. It just doesn't look "right" hence the arguments.
