(1) A person against whom recovery is sought who has a criminal conviction pursuant to state laws prohibiting the illegal sale of controlled substances or the Comprehensive Drug Abuse Prevention and Control Act of 1970 (Public Law 91-513, 84 Stats.
(1236, codified at 21 U.S.C. Sec. 801 et seq.), is estopped from denying participation in the illegal market for controlled substances. Except as provided in paragraph (2), this subdivision does not affect the plaintiff's burden of proving subparagraphs (A), (B), and (C) of paragraph (2) of subdivision (b) of Section 11705.