On the full video clip, they said that there were multiple controllers, I think one for each axis, maybe another on engines. The Canberra was not taking off, it was doing a low slow pass along the runway centreline or thereabouts.
The controllers were all located outdoors and had visual on the jet. The eyewitness commentary describes how there was a sudden silence in the chatter between the controllers as control was lost, and then it speared in.
The commentary says that the press was asked not to show what happened, but they were already packing their gear and heading for the studio with their exclusive.
I have the full clip on VHS , I will see if I can convert and post it.