Counter-payment

He has a legal claim over the calf, which is a counter-payment for the bull the other owner slaughtered.

Similarly if a bank has paid £100,000 up front to a local authority under a void interest rate swap transaction can it possibly make sense to allow restitution to the bank where the local authority has made no counter-payment but to deny restitutions to the bank where the local authority has made one counter-payment of £10 so that the consideration for the payment has not totally failed?

The rule in many African societies is that if there is a divorce the marriage payment and the counter-payment must be returned.