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    Diane L. McGimsey

    Partner

    Diane L. McGimsey Headshot Photo Portrait backdrop

    Los Angeles

    +1-310-712-6600

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    mcgimseyd@sullcrom.com

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    Diane McGimsey is a member of the Firm’s Litigation Group and a co-head of the Firm’s Employment Law Group. Before joining S&C, she served as a law clerk to Justice Clarence Thomas of the U.S. Supreme Court and to Chief Judge J. Harvie Wilkinson III of the U.S. Court of Appeals for the Fourth Circuit.

    Ms. McGimsey represents clients in a wide range of federal and state litigation matters at both the trial and appellate level, with a particular focus on the defense of private class action securities and antitrust litigation, employment litigation and whistleblower litigation, as well as handling matters for clients as plaintiffs in significant commercial disputes. Her practice also includes internal workplace investigations and investigations by the Department of Justice and the Securities and Exchange Commission.

    Community Service

    • Member of Board, Western Justice Center
    • Member of Board, Salvatori Center for the Study of Individual Freedom
    • Member of Resource Board, National Association of Women Judges

    Speaking Engagements and Publications

    • “Navigating Leadership Opportunities: the Board, C-Suite, Investors and Legal,” TechGC Los Angeles Women’s Collective Dinner (February 2024)
    • “United States Supreme Court Updates,” 2023 Institute for Corporate Counsel (December 2023)
    • “What To Expect From High Court’s Whistleblower Case,” Law360 (co-author) (July 2023)
    • “The Evolving Workforce: Remote and Hybrid Work, Unionization Pressure, Act Your Wage, and Quiet Resignation,” 28th Annual Stanford Directors’ College (June 2023)
    • “Employers’ Guide to Return-to-Work Considerations During the COVID-19 Outbreak,” Reuters Westlaw (co-author) (April 2020)
    • “Expert Q&A on Seeking or Opposing Certiorari in the US Supreme Court,” Practical Law Litigation (co-author) (February/March 2018)
    • “Expert Q&A on Best Practices for Amicus Briefing,” Practical Law Litigation (author) (August/September 2016)

    Spotlight

    Annie Ostrager and Diane McGimsey Author Law360 Article on Supreme Court’s Decision to Review Murray v. UBS Securities

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    Diane McGimsey and Adam Paris Selected as Los Angeles Business Journal’s “Leaders of Influence” 

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    Experience

    Securities and Complex Commercial Litigation

    • Volkswagen AG in its landmark $14.7 billion settlement that solves civil claims related to 475,000 2.0-liter diesel engine vehicles in the United States. The resolution was achieved with multiple government agencies, 44 U.S. states and private plaintiffs. Also advised Volkswagen on its 3-liter class action and regulatory settlements
    • Real estate investor Richard D. Cohen in obtaining a favorable ruling in a federal bench trial in the Southern District of New York over Mr. Cohen’s personal liability for a loan obtained by entities he controlled to buy a San Francisco residential apartment complex known as Rincon Center
    • BP p.l.c. in defeating a securities class action litigation arising out of the August 2006 shutdown of the facilities in Prudhoe Bay, Alaska

    • PacWest in securities litigation arising out of the 2023 banking crisis following the closures of Silicon Valley Bank, Signature Bank and First Republic Bank
    • InnovAge Holding Corp. in securities litigation relating to its IPO and the imposition of regulatory sanctions by the Centers for Medicare & Medicaid Services and certain state regulators
    • SVB Financial group in litigation against the FDIC arising out of the FDIC’s seizure of almost $2 billion of SVB Financial Group’s account funds
    • JPMorgan Chase and its affiliates in connection with litigation related to residential mortgage backed securities
    • CIM in litigation over permitted uses of the Dolby Theatre in Los Angeles, a live-performance auditorium used to host the Academy Awards
    • Standard Chartered Bank in investor arbitrations and litigations and bankruptcy proceeding relating to investments to feeder funds to Bernard L. Madoff Securities
    • RBC Capital Markets and other underwriters in a class-action litigation relating to the U.S. Auto Parts Network, Inc. IPO
    • Thomas Weisel Partners in a FINRA disciplinary proceeding alleging fraud in connection with the sale of auction rate securities
    • The former CEO of International Rectifier in class action and derivative litigation and trade secret and wrongful termination litigation
    • UBS Securities in class action and derivative litigation relating to the sale of Hollywood Entertainment to Movie Gallery
    • General Growth Properties (“GGP”) in an appeal of an adverse $95 million judgment in an action by a rival mall developer on a claim of tortious interference (another firm represented GGP during the underlying trial)

    Antitrust Litigation

    • Harvard University in a class action challenging the Ivy League’s agreement to offer only need-based aid
    • BP West Coast Products in defeating a class action involving alleged manipulation of retail gas prices
    • Cablevision Systems Corporation in defeating a class action challenging the bundling of cable programming
    • EnCana Corporation in multiple antitrust actions involving alleged manipulation of natural gas prices

    Employment Litigation and Investigations

    • Ally Financial in a putative class action alleging discriminatory business practices in violation of Section 1981, the California Unruh Act and California Unfair Competition Law
    • Wells Fargo in an action brought by an employee who was terminated in connection with allegations of improper sales practices in its Community Bank
    • The Former Head of Alternative Products of a major financial advisory firm in a gender discrimination action
    • A financial institution in multiple ongoing investigations relating to workplace misconduct and allegations of improper business practices
    • A large non-profit organization in connection with allegations of past abuse
    • A FinTech company in conducting an internal investigation and responding to high-profile allegations of a toxic environment due to sexual harassment and misconduct
    • The Former CEO of a Fortune 500 semiconductor company in DOJ and SEC investigations relating to alleged accounting irregularities
    • A multinational manufacturing and retail company in an investigation into a whistleblower complaint alleging accounting and disclosure improprieties

    M&A-Related Litigation

    • The CEO and Chairman of Activision-Blizzard in litigation over a transaction involving the restructuring of Vivendi’s ownership
    • Amylin in expedited litigation in Delaware Chancery Court, and later in an appeal to the Delaware Supreme Court, relating to a proxy contest
    • Hilton Hotels in litigation relating to its acquisition by Blackstone
    • Mitsubishi UFJ Financial Group in litigation relating to its acquisition of UnionBanCal Corporation
    • Swift Transportation in litigation relating to a going private transaction

    Rankings and Recognitions

    • AmLaw Litigation Daily – Runner Up, “Litigator of the Week” (January 2022)
    • Benchmark Litigation – Labor & Employment Star (2021, 2022, 2023, 2024)
    • Los Angeles Business Journal – recognized as a “Leader of Influence” (2022)
    • Daily Journal – Top Women Lawyers (2016, 2017, 2018)
    • Law360 – Rising Star in Banking (2015)
    • Los Angeles Business Journal – recognized as one of the “Women Making a Difference” in Los Angeles (2014, 2015)

    News

    Publications, Videos and Podcasts

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    Credentials

    Education

    • UC Berkeley School of Law, J.D., 2002
    • Claremont McKenna College, B.A., 1999

    Bar Admissions

    • California

    Clerkships

    • The Honorable Clarence Thomas, United States Supreme Court, 2003-2004
    • The Honorable J. Harvie Wilkinson III, United States Court of Appeals, Fourth Circuit, 2002-2003

    Related Practices