In all fairness, why should there be a 'settlement'? Cardiff agreed to buy a player for X amount. The fact he didn't get to play a game for them due to tragic circumstances is neither here nor there. They agreed a fee, they now need to pay it. If I was the owner of the selling club, no way would I agree to anything less than what was agreed.
Edit - and if anything, I'd look to sue them for withholding funds owed to them!