The comment prevalent with the announcers was that the transfer was "so quick" after the catch that it might have appeared to Merriweather that Bradley never had complete control of the ball and dropped it. One of them even tried to correlate it with a double play ball at second base where the transfer also happens very quickly. In those circumstances the "catch" of the ball is ruled a force out the majority of the time and the drop is attributed to the transfer. However, one is a catch of a batted ball while the other is a catch of a thrown ball.
The whole situation is just another example of the "holes" encountered in the mechanics and areas of responsibility in the MLB umpire coverage. Perhaps they need to have two U2s; one to take care of the base and one to take care of the gap between UL and UR?
U7