What is the ruling if a claimant with a single witness in monetary matters offers their own oath in addition?

Primary text

If the claimant possesses only one witness regarding a monetary right, the judge informs them they may swear alongside their witness to establish the right. If the claimant refuses to swear, preferring only the defendant's oath, the judge administers the oath to the defendant. If the defendant swears, the right is extinguished. If the claimant later attempts to swear an oath with their witness after the defendant has already sworn, the claimant is not heard, as they were capable of swearing when the right was due.