Another BEA Viscount incident I remember reading about was at Brussels in the 1960s.
IIRC there was fog and the Viscount was told to backtrack runway 20 and take off on runway 25 (now 25R). However the aircraft took off on 20 straight towards another Viscount taxiing out.
Neither aircraft saw the other and ATC only realised the mistake when BEA called airborne off 20.
This was a case of mind set when being told to "Backtrack" the non active runway.