Your account was delinquent therefore, the charge qualified for the Franchise Tax Board (FTB) Intercept Program. If you filed a joint return with someone who had an account with DRR and was delinquent, then the tax refund qualified for tax offset.
Government Code 12419.8 states that the Controller may, at his or her discretion, offset any amount due to a county that has been reduced to a judgment, contained in a court order, or from a bench warrant for payment of any fine, penalty or assessment.