Nobody "fixes" tickets in the UK. The word "fix" means either to set or to repair over there, not to do somethng underhanded.
Actually, I strongly suspect that "fixed" is derived from the nautical term - where you establish a position based on known readings or facts. In any case, only someone blinded by their prejudice would believe that anyone would put in a formal government memorandum that facts are being blatantly misrepresented.