Filing of a lawsuit for recovery of undue payment made to the consenting intervening party. Prior arbitration award determining the quantum that was reversed in favor of the true creditor in proceedings conducted without the participation of the consenting intervening party. Statute of limitations for restitution of unjust enrichment, which began to run upon the partially undue payment, and not upon the rendering of the arbitration award, given that the arbitration proceedings did not suspend the statute of limitations, since the consenting intervening party did not participate therein: