If Mckinsey had brains they would use this as their out. Very neat for them. We can prepare Mckinsey's statement: 

"It has come to our attention that Eskom never had the legal authority to enter into the settlement agreement with us and hence we have been advised it is invalid in law and have decided to return the money".

Otherwise they will need to a lot of gymnastics to explain how a supposedly maverick Sager did a deal wholly in their considerable financial interests; and why Eskom (who they knew was close to their partner who they acknowledged in writing was a corporate governance risk) was such a generous negotiating partner making crazily high payments that Eskom had no need to make for a never consummated, supposedly 'at risk' contract that MCKINSEY elected to withdraw from and did not properly deliver on.