And the system should detect that and kick the person right away.
Not going to happen. Mentors are just people, they aren't machines. If the mentor roulette threw me into Ultima HM tomorrow, I can pretty much guarantee you I wouldn't remember the fight. The last time I did it synced was probably over a year ago. If you think I'm gonna remember every mechanic of that fight, you're nuts.

You need to adjust your expectations a little bit, otherwise you're going to continue to be disappointed.