(a) Notwithstanding Section 821.005, the retirement system may deduct the amount of a person's indebtedness to the retirement system from an amount payable by the retirement system to the person or the person's estate and the distributees of the estate.
(b) If the retirement system makes a payment to a participant who is deceased and the payment is not payable, the retirement system may deduct the amount of the payment from any amount payable by the retirement system to a person who received the payment or to that person's estate and distributees of the estate.