In Re Guaranty Insurance Services, Inc., 343 S.W.3d 130

Paralegal Clyde Williams worked at Godwin Pappas from 2005 to 2006, billing hours in the underlying Trans-Global/Guaranty suit.
Strasburger & Price, LLP later represented Guaranty in the related indemnity proceeding; Williams applied to Strasburger in Oct. 2008 and was hired in Jan. 2009.
Strasburger ran conflicts checks and instructed Williams not to disclose confidential information gained from prior employment; he signed a confidentiality agreement and acknowledged duties in the Employee Information Handbook.
Williams failed to disclose his prior involvement in the underlying suit; Strasburger later learned of the conflict from Kane Russell after Williams’s access was discovered.
Trans-Global moved to disqualify Strasburger; the trial court granted the motion, finding a conclusive presumption of shared confidences due to Williams’s work on both sides.
Supreme Court granted mandamus relief, conditioning on vacating the disqualification order, and held Strasburger’s screening measures were effectively implemented and sufficient to rebut presumption.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether nonlawyer work on both sides triggers conclusive presumption	Guaranty argues presumption applies; Williams’s work on both sides could contaminate confidences.	Strasburger contends screening and lack of actual shared confidences rebut presumption.	Presumption rebuttable under effective screening.
Whether Strasburger's screening was effective	Presumption remains if screening ineffective; Williams’s access should have been barred.	Formal, institutionalized screening was thorough and reasonably prevented disclosure.	Screening deemed effective; presumption rebutted.
Whether the supervising attorney’s knowledge of the conflict was reasonably foreseeable	Strasburger should have known Williams’s prior involvement.	Record shows supervising attorney reasonably should not have known; rebuttable presumption applies.	Reasonable belief that conflict was not known; presumption rebuttable.
Whether mandamus relief was proper to overturn disqualification	Disqualification was an abuse of discretion given screening effectiveness.	Disqualification appropriate absent effective rebuttal.	Mandamus relief proper; disqualification order vacated.

In re American Home Prods. Corp., 985 S.W.2d 68 (Tex.1998) (nonlawyer confidences presumptions; rebuttable where appropriate screening exists)
Phoenix Founders, Inc. v. Marshall, 887 S.W.2d 831 (Tex.1994) (six-factor screening test; ultimate question is effectiveness of measures)
In re Columbia Healthcare Sys., L.P., 320 S.W.3d 819 (Tex.2010) (nonlawyer screening; knowledge and actual work affect presumption)
Grant v. Thirteenth Court of Appeals, 888 S.W.2d 466 (Tex.1994) (cautionary duty to prevent nonlawyer disclosures; relies on ABA ethics guidance)
In re Prudential Ins. Co., 148 S.W.3d 124 (Tex.2004) (orig. proceeding; framework for mandamus relief in disqualification contexts)
NCNB Tex. Nat’l Bank v. Coker, 765 S.W.2d 398 (Tex.1989) (orig. proceeding; standard for mandamus-related disqualification review)