This being so, one would question why Esso was allowed to claim for the sum it was statutorily liable to pay the owner of the jetty for colliding with it. This payment was not consequent on the damage to the ship, it was consequent on the damage to the jetty, coincident though the two harms are apt to be. The House of Lords held (a somewhat indeterminate decision) that this grounded a claim in tort rather than a claim for release within the Scottish legal sense.   There are two factors which should, however, be noted: That Esso’s payment to the jetty owner reduced the defendant’s liability, in as much as the jetty owner would have had to give credit to Hall, Russell for any sums received from Esso and, was involuntary, in as much as the payment was due by Statute. It could well be argued that in English law at any rate, this would result in a claim for a quasi contractual indemnity or, what is known as ‘restitution’ and ‘unjust enrichment’. Nonetheless, whatever the merits of any legal concepts used, Esso was indeed able to recover this payment. This being so, why could Esso not claim the other sums on the same basis? Because, the House of Lords said that Esso’s payment: Did not discharge the defendant’s liability to the crofters and BP. As to the first point it is simply not credible that any court would order Hall, Russell to make a payment of damages to a party who had already received compensation for the injury. Similarly, it is not really quite realistic to describe Esso’s payment under TOVALOP as ‘voluntary’ as although the agreement itself is entered into on a voluntary basis, once having been entered into it is then legally binding. Indeed, the payment to BP was paid under an arbitration award which is of course legally enforceable.