Here's a guess.Both institutional blocs were sold to the same counterparty who (maybe) entered into a deal with them prior to trial ann in case it all went pear-shaped. They want to do something else with the shell and needed a cheap stake to kick off their t/o process at less than cash value.
FIL and Allan Gray have done their dough and interest in the investment, so what do they care the intentions of the buyer so long as they get shot of their big parcels.