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.
This assumes the British Shopping Authority bothered to install a STOP button in the Jetty.... as the B744 v Stand 127 at LHR showed, they didn't in that case... or rather had a program to install them that ran over the next X years (X being a large number).
Even after the accident at LHR, when the AAIB went back to see the "professional" modification BAA / HAL had made, they found a random button installed, confusion over which button did what, and the sign for the button "propped up" on the button - not even installed.
The AAIB report makes sorry reading, especially if you were the (presumably now ex-) Safety manager for HAL
