Oldlae:-
"had some officers listening while "brakes" was called from various points in the hangar, it was hilarious to us,"
If it was the same incident, I was one of the hilarious officers. I arrived at St. M. in March 1965 as a newly qualified Shackleton pilot to join 206 Sqn. Shortly afterwards, I was lumbered with being junior member of a Unit Enquiry into an accident which fits your description.
The Shack's wingspan was too great for them to go into the hangar forwards, and the hangar had metal tracks along which travelled two linked flat trollies called "skates", the width apart of the main wheels. The aircraft was positioned sideways on to the hangar, then pulled up onto the skates. With the tailwheel turned sideways, the tractor then towed the whole thing sideways into the hangar. Once inside there was no room to get a tractor behind the aircraft to move it down from the skates, so the procedure was to attach a chain to one main landing gear, and pull it forward off them. The skates stood about 4 inches above the floor of the hangar, so once the wheel started to roll down the ramp, the brakes had to be applied to bring the aircraft to a halt.
On this occasion the aircraft did not stop, the No.3 prop hit the back of the tractor, bent, and continued forward and bent the steering wheel of the tractor. Luckily the driver abandoned tractor in time to avoid getting squashed.
We had to establish what had caused it - there was discussion of whether the rigger on the brakes heard the call for brakes, ( hence the pantomime you saw), but there was also a question of whether anyone had checked that the pneumatic brake system was fully charged.
As I recall, we tried to say that it was just an unavoidable accident, but were told in no uncertain terms to reconsider, as the procedure had been carried out hundreds of times before without incident. I think eventually the Chief in charge was fined for negligence.