It's inconsistently interpreted. The most egregious, to me, was taking away the Cowboys score in last years NFC title game. Clearly a catch IMHO, and I'm no Cowboys fan.
Yesterday Gary Barnidge (Browns) caught the ball on his back, between his legs. He contorted and managed to get the ball into his arms. Compare this with the "ball cannot move" judgement made in many other catches. It decidedly MOVED from his legs to his arms. I don't understand that interpretation.
And watching a carrier control the ball out of bounds is an inconsistent policy . Aside from personal fouls, once a ball carrier is out of bounds the play is over. It's contrary to the game to continue judging the play after the whistle.
They're essentially saying the player can get tangled up with photographers, other sideline personnel, cables, benches, gatorade, and the refs are supposed to KEEP WATCHING through this to see if the ball moves? As if all of THAT is part of the field of play?