It's individual people that are flexible or inflexible...even within an organisation as structured as the RAF. There are two factors to the outcome.
One, the attitude and qualities of the person being approached.
Two, the attitude and qualities of the person with the request.
If I was a desk officer (which I might have been...or similar) and a good egg came to me with an honest cause and a polite request I would (and on many occasion may have) gone into bat on their behalf. Nine times out of ten with the right result for all concerned.
On the other hand if I was ever approached with the "do this or else...." option, being a bl**dy minded SOB who never really gave a toss about his career, my answer would have been...."bring it on" (and on more than one occasion.........it was!)