So after the towbar broke, the jet continued on for another 20m before running over the tug? I assume that, because the brake-rider wouldn't be able to see the tug over the nose, that the tug driver and he/she were in radio contact thru the intercom and probably would've heard the call "BRAKES"?!
Perhaps the tugs now need those long flag poles and bright orange flags the Toorak Tractors have at minesites so the drivers of 250t Haul-Packs don't squash them without even seeing them...
I guess there will be more to the story but...
And Mr Anderson, good to see your spinning on this subject is as accurate as your's on NAS!