When we went on the tour of Dolphin Stadium during Web Weekend, we were taken into the media center that controls the HD scoreboards. Jeff is the guy who runs the place, and he was gracious with his time, and explained all that goes on in there.
One of the things he talked about was how he handles replays of questionsable calls. If it favors the Dolphins, he will show replays from as many angles as possible as quickly as possible to aid the Dolphins staff in making a decision to challenge the play. But, if the opposing team might benefit and make a challenge, he won't show any replays.
This past Sunday, there was the play where Donald Driver caught a pass and it was ruled incomplete by two officials.
As it happened, I thought "I bet Jeff won't be showing that replay on the scoreboard." And sure enough, they started doing crowd shots, and had a shot of the players on the field. And, then, out came the challenge flag for the Packers.
It wasn't until after the ref went under the hood that the replay was shown/
Jeff also noted that there's a league rule that only the network's replays can be shown on the scoreboard once the challenge is made. So, as expected, that's what we saw - and it was obvious because they were not in HD as the rest of the camera shots are during the game.
It was cool to see it happen just as he called it.