A good assessment would be difficult to “cheat” on even if you were given percentages/calculations. You are not going to get assessed on whether you could work out the calculation, you are going to get assessed on expressing why the calculation is relevant/important.
Typically in case studies there are far too many points for an individual to either pick up in the timeframe, or present back in their discussion with their assessor. Therefore, just going on what someone else told you they spoke about is very short sighted. 1) they could be wrong (even if they got the job) and 2) they might not have picked up the most relevant or important parts of the case study. Added to that, if you can’t think beyond the immediate answer, you’ll look pretty one dimensional in the follow up discussions, and that’s assuming you will be asked the same questions as the informant.
I’ve seen plenty of times on assessment feedback forms where something along the line of “pretty sure they were given the context of the assessment ahead of day, and were over-prepared” is noted. As a facilitator, I have also flagged when I thought someone was “cheating” (eg using their phone/pre made notes) or felt they had somehow prepared ahead of the assessment.
For anyone who is really trying to drill down into the specifics “answers” of a case study - you are not thinking like a lawyer. This is sometimes my criticism of questions I receive on here - people are looking for these cookie cutter answers they think will bring success, and it really doesn’t work like that.
You need to present your own “analysis” whether on an application form or at interview. You need to respond with the information you are presented with, not someone else’s.
Finally, these people are just creating more work for HR teams. It’s often why they have to re-write AC materials each cycle (which isn’t cheap or quick to do). Although to be fair, they often have to be replaced as candidates may have seen the materials last cycle too.