Depends on the subject right? A Level Further Maths modules were (at least when I did it) typically at a very high level, and you couldn't wing them, you really needed to understand the material.
Like I said you do need a grasp of the subject matter still, but I think if the exam changed a bit to something you should technically be able to work out with the same knowledge, but isn't what's expected, a lot of people would struggle. It was always a common complaint anyway right - 'that was nothing like the past papers!' etc.