I am interested that clearing is higher than insurance. Kinds at my school are very risk averse. the only ones I know who have done clearing have bombed grades for insurance as well. So what that suggests is that there is not a very big gap between firm and insurance offers : which make sense . The lowest grades I could find for politics at a kind of standard uni (ie not an FE college and not in the bottom 10 of league tables) was BCC. The highest if I take out the most prestigious institutions is about ABB, so not much wiggle room there.
I would imagine those who are able enough to have firm offers I the A* AA range would take an insurance down to about AAB but not much lower so again could fall down.
I think the 78 by the way are those who are known to have recirculated the maths paper/ have been found to have acted upon it is some way. My spies tell me 78 equates to a whole centre , so there is something very dodgy. The two people released will have been released pending enquiries I assume. No mention of being cleared of charges.