theory_id,filing_id,theory,party,role,basis 325,44,Proportionate Responsibility — Responsible Third Party Designation,Kassab,defense,"Under Tex. Civ. Prac. & Rem. Code § 33.004 and § 33.011(6), persons who caused or contributed to causing harm may be designated as responsible third parties for fault apportionment. Notice-pleading standard applies. Court 'shall grant' leave if pleading is sufficient under § 33.004(f)."