Kathaleen McCormick took on the role of chancellor, or chief justice, of the Court of First Instance last year, the first woman in that role. On Wednesday, she was assigned the Twitter lawsuit that seeks to force Musk to complete his deal for the social media platform, which promises to be one of the biggest legal battles in years. “He already has a history of not tolerating some of the worst behavior that we see in these areas when people want to get out of deals,” said Adam Badawi, a law professor who specializes in corporate governance at the University of California. Berkeley. “She’s a serious, no-nonsense judge.” Sign up now for FREE unlimited access to Reuters.com Register In contrast to Musk’s brash and volatile demeanor, she’s known for being soft-spoken, approachable and friendly — but also someone who stands her ground. It supports respect between parties and integrity in legal conferences. “We’ve always had each other’s backs, we’ve always gone out for drinks after fights and maintained that level of civility,” he said at a gathering at the University of Delaware this year. After weeks of conflicting tweets suggesting Twitter was hiding the true number of fake accounts, Musk said Friday he was ending his $54.20 per share acquisition of Twitter, worth $44 billion. On Tuesday, the social media platform sued. read more According to legal experts and court records, judges have ordered reluctant buyers to shut down takeovers only a handful of times. One of them was McCormick. Last year, McCormick caught the attention of Wall Street traders by instructing an affiliate of private equity firm Kohlberg & Co LLC to close its $550 million purchase of DecoPac Holding Inc, which makes cake decorating products. She described her decision as “revealing a victory for the certainty of the deal” and dismissed Kohlberg’s arguments that she could pull out due to a lack of funding. The case has many parallels with the Twitter deal. Like Musk, Kohlberg said she is leaving because DecoPac violated the merger agreement. Like Musk, Kohlberg argued in part that DecoPac failed to maintain normal operations. There are also differences. Musk’s deal is much larger, involves a company that trades on Twitter, and could have ramifications for Tesla Inc, the electric vehicle maker that is the source of much of Musk’s fortune. In other cases, he has sided with shareholders when they clashed with management. Last year, he blocked energy company The Williams Cos Inc from adopting a so-called poison pill anti-takeover measure, saying it breached their fiduciary duty to shareholders. Last month, he said Carvana Co ( CVNA.N ) shareholders could sue the board for immediately offering shares to select investors when the share price was depressed during the early pandemic. A graduate of Notre Dame Law School, McCormick began her career with the Delaware chapter of the Legal Aid Society, which helps low-income people navigate the court system. She went into private practice “primarily for financial reasons,” she told the Delaware Senate during her confirmation hearing, joining Young Conaway Stargatt & Taylor, one of the state’s premier business litigation firms. She joined the Court of First Instance in 2018 as vice-chancellor and became the first woman to lead the Court of First Instance last year. Despite her soft-spoken manner, Eric Talley, who specializes in corporate law at Columbia Law School, said he doubts Musk will be fooled by McCormick. “I wouldn’t put my bets on Chancellor McCormick suddenly becoming weak,” he said. Sign up now for FREE unlimited access to Reuters.com Register Reporting by Tom Hals in Wilmington, Delaware and Hyun Joo Jin in San Francisco. edited by Noeleen Walder and Jonathan Oatis Our Standards: The Thomson Reuters Trust Principles. Tom Hales Thomson Reuters Award-winning reporter covering US courts and law from the COVID-19 pandemic to high-profile criminal trials and Wall Street’s biggest failures with more than two decades of experience in international financial news in Asia and Europe.