Did the Referees Throw the Dallas Cowboys vs Detroit Lions Game?

Obviously this is nothing more than speculation, but the circumstances are very sketchy. Late in the fourth quarter during a game the Detroit Lions were winning, they were moving down the field looking to put the game on ice. Then, Dallas Cowboys rookie linebacker Anthony Hitchens committed what was obviously pass interference against Brandon Pettigrew on a crucial third down. The refs threw the flag, talked about the call, made the announcement that it was a penalty, and then picked up the flag. You can see the entire thing here. To our knowledge, that sequence of actions never occurs. So why was it that, after making the announcement, did the refs change their minds? It's almost as if there was an ulterior motive behind the decision -- or someone at the top pulling strings. What do you think? Was this just a case of a late mind change, or is there something more to this non-call?