Hmmm, a good question; if the dispatcher meeting the flight was on the Jetway; they could and should have activated the STOP button. Which would have alerted the Flt Deck by means of Bright Flashing Stop signs that can't be missed.
However, sometimes the Dispatcher does not arrive until the aircraft is already on stand if things are busy!
Mind you, the view from the Jetway is not that good; indeed the Stop Button and Jetway controls are on the terminal side of the Jetway so, the view is quite limited until it gets noisy!
Apparently the Jetway had to be lifted off the aircraft by a crane and is now U/S.
