BEagle
You are forgetting that in that time long long ago it was a "Can Do" Airforce.
A phone call direct to the Station Commander,who then called the SDO and Orderly Sgt, would have a good chance of having several SNCOs including Armourers at the line in a few minutes. I was not at Brawdy so I do not know how they operated, but there is a good chance that some of the aircraft had valid Before Flight Servicings ready for the first wave and that several gun packs were loaded,in the Armoury, and ready to go as well. The Staish would also, no doubt, have authorised himself for the sortie! So it could have been possible to launch in about an hour from the call. So saying that it is still too late for an intercept. The biggest problem would have been persuading the Guard Room to hand out the keys!
All this without a herd of Duty Holders, Health and Safety Persons or a Diversity Advisor.
We heard nothing about a Hunter at the time. I strongly suspect it is all fiction.