I've seen that put forward a lot. Here's a screencap they posted over at GWB: http://i20.photobucket.com/albums/b207/newpagodi/2072.jpg Arm is coming up, ball is just barely in the frame. Don't see that in the rules. http://i20.photobucket.com/albums/b207/newpagodi/2055.jpg A few frames before the previous picture. SS, who hadn't exactly sprinted to get there, is under the ball, holding his arms out to say that he's got it, and setting up to make the catch. That's when the umpire decided to make the call. I've heard a few umps from various sources say that you usually make the call on plays like that when an infielder sets up under it. Though granted, I've heard others say they would never make the call at all.