Seller's Action for Payment and Buyer's Defense of Non-Conformity

A seller sued a buyer for payment of goods delivered under a contract, but the buyer raised the defense of non-performance by the seller, arguing that the delivered items did not conform to the specifications stipulated in the agreement. The Court of Cassation partially quashed the lower court's decision because, while acknowledging the buyer's right to invoke non-performance, the appellate court failed to properly establish whether the alleged non-conformity was of such gravity as to justify the complete refusal of acceptance and payment, thereby failing to legally justify its conclusion denying the seller's claim.