Whose testimony prevails when the parties dispute the specific identity of the slave for which payment was offered for its return?

Primary text

If the dispute concerns the identity of the slave for whose return the payment was stipulated—one party claiming they returned the specific slave qualifying for payment, and the other claiming the stipulation was for the return of a different slave not returned—the owner's statement prevails. This is because the owner is the most knowledgeable of their stipulation, and since the claimant alleges a specific condition in this contract which the owner denies, the principle is the absence of that condition.