How is this NOT a fumble??
NFL Rule 3, Section 22, Article 2, Note 2. When [an offensive] player is holding the ball to pass it forward, any intentional forward movement of his arm starts a forward pass, even if the player loses possession of the ball as he is attempting to tuck it back toward his body. Also, if the player has tucked the ball into his body and then loses possession, it is a fumble.
By the rules the game was played with, it was not a fumble. You can never change that. You can argue that Calvin Johnson caught that TD pass, you can argue that this was a fumble, but the rules say the opposite. The game has rules. All those overtime games won by the first team kicking a field goal ... they happened. That loss of possession by Brady as he attempted to tuck the ball ... still a forward pass start, and therefore not a fumble. The announcers simply didn't know the rule. They kept crowing that Brady was tucking the ball, which is exactly qualified it as an incomplete pass, and not a fumble.
The rule seems designed to make it easy on the officials ... any forward motion of the arm makes it a pass, which is either complete, incomplete or intercepted. Since it hit the ground it was incomplete. At full speed, I don't see how the official is supposed to figure out the QB is pump faking or passing.