Is there anything you can take from the DVLA introducing the hazard perception element to the Driving Theory Test? Similarities to be drawn here between most students passing in the notice period given with those that don't having to pay extra for further revision material, more time to study, a chance they could fail on that part and have to sit again - having already paid the DVLA for a provisional license on their initial understanding of what they would have to do to pass.
That affected the whole population rather than the niche area of actuaries so surely there must be a ton of legal cases based on your arguments proving the DVLA acted illegally with court orders proving as such that you can use as precedents? Unless the whole population decided that modernising and improving the exams was necessary and that it was impossible to introduce without affecting a few people in the crossover no matter how much notice they give (How dare they not cater for those who don't pass 8 CT exams in 16 years!). I'm sure out of the whole population not everyone would be sheep and there would be some enlightened souls such as yourselves who won at court, so I would suggest looking there.