Agree Nin, but maybe it's just cheating by another name?
The case is to establish the Nantes' owners/directors employed an illegal agent to factor the sale of a player. They allowed that agent the scope to arrange illegal flights by unqualified pilots which ultimately resulted in the death of that player. That's the fundamental issue that needs to be ruled upon by the French Courts, and the facts as we understand them are cast in stone.
The more contentious issue is the extent of the consequential losses suffered by CCFC as a result of those actions. Whether they consider CCFC's monetary claim on the back of a positive ruling to be pure speculation and not realistic is up for grabs.
As the entire transfer fee/footballing penalties have now been settled, there should be no counter claim from Nantes to offset any award - they have the money and the accrued interest in the bank. I expect CCFC to at least get that back but the "consequential losses" arrising from what "might have been" had Sala played for the club seem very optimistic.
Mind you, ask for £15M and that's the max you'll ever get - ask for £100M and who knows?