(a) In the determination of any case arising under this part, the rule of res judicata is applicable only if the liability involved is for the same year as was involved in another case previously determined.

(b) Notwithstanding the holding in Pope Estate Company v. Johnson, 43 Cal. App. 2d 170, in any action filed pursuant to Section 19382 (relating to taxpayer suits for refund), in addition to the defenses or relief sought in the action, the Franchise Tax Board shall assert in defense only those unpaid liabilities of the taxpayer for the same year which are evidenced by any of the following:

(1) A final proposed assessment.

(2) A notice of tax due.

(3) A final notice of action. In addition, any refund claim of a taxpayer for the same year resulting from a federal audit adjustment made subsequent to the filing of the action need not be asserted by the taxpayer in that action.

(Added by Stats. 1993, Ch. 31, Sec. 26. Effective June 16, 1993. Operative January 1, 1994, by Sec. 83 of Ch. 31.)