There was a bit of a strange situation at the end of the second period of Game 3 of a 2011 NHL Playoffs first-round series between the Capitals and the Rangers. With the game tied, somehow, a puck trickled into the Capitals' net as the buzzer sounded. It was a bang-bang call, since the whole puck has to be over the goal line.
But it really wasn't as close as NBC made it seem. As you can see in this photo, the green light is on and the puck isn't over the line. And yet, for some reason, NBC says there are 0.2 seconds left in the period. This is because they were using the unofficial stadium clock, instead of the official clock. How this continued is beyond me, especially considering how important it was to make viewers know just how close the goal really was.
In the end, the officials made the right call, and the game remains tied. Thankfully, they didn't rely on NBC to give them the proper amount of time.