People / Debbie McComas
McComas Debbie

Debbie J. McComas

Partner | Co-Chair - Pro Bono and Public Service Committee

Debbie McComas has argued before the Texas Supreme Court, petitioned the United States Supreme Court, helped draft model patent jury charges for the Federal Circuit Bar Association, and defended foreign sovereigns from multiple continents. Whether before the highest courts or a trial court in rural East Texas, Debbie dedicates herself to her clients and brings practical solutions to uncommon problems.

Debbie has led teams in significant appeals and trial matters throughout the country. She argued In re Schmitz to the Texas Supreme Court, a case that set the standard for shareholder derivative suits against Texas corporations. Debbie defends foreign corporations and sovereign nations in cross-border disputes, often obtaining dismissal on jurisdictional grounds before discovery. Her extensive knowledge of both state and federal procedure and her ability to quickly grasp facts and legal issues allows her to aid her clients on a broad array of subjects, be it oil and gas or patent infringement.

Debbie is particularly active in the Federal Circuit Court of Appeals, where she has appeared in more than 25 cases, including appeals from both federal district court judgments and final written decisions from the PTAB.

A consummate advocate, Debbie is also dedicated to her community and is proud to have served as co-chair of Haynes and Boone’s Pro Bono and Public Service Committee. She also serves as a member of the Board of her church. She is honored to have received the Light of Justice Award from the Texas Defender Service for her pro bono achievements.

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Selected Client Representations
  • Successfully argued case of first impression regarding shareholder derivative actions to the Texas Supreme Court
  • Representation of gas well operator and owner in arbitration seeking damages from service company that damaged well during cement operations
  • Representation of oil and gas operator’s interests in lawsuit over joint operating agreement
  • Representation of lenders in various lawsuits involving oil and gas interests
  • Representation of real estate interests in property disputes
  • Representation of lender in $2.5 billion lender liability lawsuit stemming from the bankruptcy of Adelphia Communications Corporation and its subsidiaries
  • Representation of foreign corporations in trade secrets disputes
  • Representation of creditors in judgment enforcement proceedings, including enforcement of a more than $100 million judgment against an Indonesian corporation
  • Representation of Cayman Islands bank in West Texas lender liability lawsuit, successfully affirming dismissal for lack of personal jurisdiction
Professional Affiliations and Engagements
  • Federal Circuit Bar Association (2008-present), Model Patent Jury Charge Sub-Committee Member (2008-2009)
  • Co-Chair, Dallas Bar Association Judiciary Committee (2006)
  • Co-Vice Chair, Dallas Bar Association Judiciary Committee (2005)
  • Co-Chair, Dallas Bar Association Judicial Evaluation Poll SubCommittee (2003, 2004)
Awards and Recognition
  • Recognized as a "Legal Lion" by Law360 for a defense victory in an intellectual property trial in the Eastern District of Texas, 2019
  • Selected for inclusion in The Best Lawyers in America, Woodward/White, Inc., for Appellate Practice, 2020-2022, Commercial Litigation, 2022
  • Honored with the Texas Defender Service Light of Justice Award, 2014
  • Texas Super Lawyers - Rising Stars, Thomson Reuters, Appellate, 2004-2008


J.D., Tulane University, 1995, cum laude; Managing Editor, Tulane Maritime Law Journal; Associate Justice, Tulane Moot Court Board

B.A., Austin College, 1990, with honors





Press Release
Haynes Boone Team Secures Appellate Victory in Federal Circuit
January 13, 2022

A Hayne Boone team led by Partner Stephanie Sivinski persuaded the Federal Circuit Court of Appeals to uphold a rare defense judgment the firm won in an IP jury trial in the Eastern District of Texas. The Federal Circuit also reversed a smaller breach-of-contract judgment against our client, resulting in a complete defense victory in this bet-the-company case.   After a weeklong trial before Chief [...]