Michael R Leslie

• Substituted into a complicated enforcement action as lead trial counsel a mere ten days before trial at the request of the State of California. Working with the California Attorney General’s office, Mike and the team represented the California Air Resources Board in the trial of an enforcement action brought against a major vehicle and engine manufacturer. The manufacturer had brought a cross-claim against the agency, alleging regulatory and constitutional violations, and seeking sweeping injunctive and declaratory relief, including dismissal of the enforcement action. After multiple witnesses and days of trial, the manufacturer agreed to dismiss its cross-claim with prejudice and to pay CARB almost $2 million, plus an additional amount to be suspended conditioned upon the manufacturer’s future compliance with the engine emissions certification laws, thus resolving the case.
• Obtained a defense verdict after a five-week jury trial in federal court in San Francisco. As lead trial counsel, Mike represented a multinational energy company against claims for compensatory damages of $25 million, as well as punitive damages, brought by a local governmental body that had been compelled to clean up wastes left over when its tenant, an oil recycler, went out of business. After only two hours of deliberation, the jury rendered a complete defense verdict in our client’s favor, awarding the plaintiff nothing. After the plaintiff appealed, Mike argued the case before the Ninth Circuit and won an opinion affirming the defense judgment in all respects.
• Represented a large energy company in a ten-week jury trial involving claims by a land company for cleanup of hydrocarbon contamination after substituting into the action a mere three weeks before trial. Although the plaintiff went to the jury with a damages claim of almost $70 million—raised to more than $120 million at trial—and also asserted a claim for punitive damages, Mike won a nonsuit on the punitive damages claim and obtained a jury verdict for his client on two out of the three areas of contamination at issue. The award on the remaining plume—after the verdict was reduced by more than $14 million on Mike’s successful appeal—was $3.9 million, almost $20 million less than the plaintiff’s pretrial settlement demand.
• Represented several California State agencies against an oil shipper and several other defendants who were involved in a spill of 400,000 gallons of Alaska North Slope crude oil onto Orange County beaches, forcing widespread beach closures. After extensive litigation leading to $11 million in settlements with three of the defendants and precedent-setting decisions from both the Ninth Circuit and the California Court of Appeal, Mike and his team recovered an $18 million jury verdict against the ship owner. This verdict was one of the first natural resource damage claims to go to trial and was reported as one of the ten largest jury verdicts that year.
• Represented defrauded investors in a fraud and RICO action against the financiers, attorneys, and promoters of a failed residential housing development. After pretrial settlements with most of the defendants, Mike and the team tried the case to a multimillion-dollar jury verdict against one of California’s largest banks. The case then settled on favorable terms, resulting in complete recovery for the 62 plaintiffs.
• Won summary judgment dismissing numerous tort, nuisance, and environmental claims brought by dozens of condominium owners and a condominium owners association on behalf of the client, a multinational oil company. The case arose out of a 110-unit condominium development built on a site that was a former terminal facility, which was sold by the client more than 25 years previously to another company. The plaintiffs presented a demand of more than $35 million, claiming property damage, diminution of value, nuisance damages, and emotional distress.
• Won summary judgment in a major case on behalf of the client, a large energy company. The plaintiff, a large real estate developer, claimed that historical contamination by Mike’s client led to an alleged $50 to $100 million in lost sales, costs, and damages. After almost five years of discovery and motion practice, in which Mike successfully knocked out all of the fraud, nondisclosure, and punitive damage claims, Mike obtained summary judgment dismissing all of the negligence, nuisance, trespass, and other tort claims, and reducing the damages in the case from an alleged $50 to $100 million to a small breach of contract claim over environmental consulting costs, which subsequently settled.
• Represented a group of investors who were defrauded by the registered financial representative of a large independent brokerage. After defeating the brokerage’s effort to force the case into a FINRA arbitration—including obtaining an opinion by the court of appeal affirming the trial court’s ruling denying arbitration—the team successfully litigated the case, ultimately settling the investors’ claims on the eve of trial for the majority of their investment losses.
• In a case alleging fraud in the sale of an oil field in Santa Barbara County, where the plaintiff sought millions of dollars in compensatory and punitive damages against our client, Mike obtained summary judgment on the eve of trial dismissing all of the plaintiff’s claims. Mike then defended plaintiff’s appeal of the summary judgment, winning an affirmance of the summary judgment from the court of appeal, ending the litigation.
• Regularly represents potentially responsible parties (“PRPs”) in the prosecution and defense of CERCLA contribution actions, federal and state environmental investigations, and complex multi-plaintiff and multi-defendant toxic tort actions, such as those involving the Burbank Operable Unit of the San Fernando Valley Groundwater Superfund Site and the El Monte Operable Unit of the San Gabriel Valley Groundwater Superfund Site.

Mike Leslie is an accomplished trial lawyer and negotiator who focuses on complex environmental litigation, including litigation brought under CERCLA, CEQA, common law environmental torts, and California’s Proposition 65. Mike is a leader in the fields of ESG, "Greenwashing," and state and federal Environmental Justice issues and has published and spoken widely on these topics. Mike also has deep expertise in complex commercial litigation, having prevailed in cases involving real estate, class actions, breach of fiduciary duty, fraud, misappropriation of trade secrets, and Section 17200, California’s unfair business practices statute. 

Mike has a long-standing record of successfully representing clients in the litigation and trial of high-stakes complex actions. Mike regularly represents Fortune 500 corporations, multinational energy companies, governmental agencies, and small businesses. He has tried numerous cases to verdict, negotiated complex multi-party consent decrees with state and federal agencies, and won both significant plaintiff and defense verdicts. In addition to his busy trial practice, he has also won important appeals for his clients before the California Court of Appeal and the Ninth Circuit Court of Appeals.

Mike is a leader in many of the leading environmental bar organizations and is also a frequent speaker on complex litigation and trial practice:

• Speaker, "ESG and EJ at the Crossroads," American Bar Association, Environmental & Energy Litigation, Mass Torts, Products Liability Seminar (January 2025)
• Speaker, "The Rise of ESG in Litigation: Impacts and Implications for Environmental Litigation, Products Liability and Mass Torts," American Bar Association, Environmental & Energy Litigation, Mass Torts, Products Liability Seminar (February 2023)
• Moderator, "EJ Toolkit: State & Federal Policies and Initiatives," California Lawyers Association, 31st Annual Environmental Law Conference at Yosemite (October 2022)
• Speaker, "Water Justice and Water Equity: Environmental Justice Issues in Water Law," Foundation for Natural Resources and Energy Law, 68th Annual Natural Resources and Energy Law Institute (July 2022)
• Moderator, "Environmental Justice Rises to the Forefront: Litigation, Regulatory and Legislative Impacts," ABA Environmental & Energy, Mass Torts and Products Liability Litigation Committees' Joint CLE Seminar (January 2022)
• Moderator, "Burning Issues in Climate Change: Litigation and Legislation in 2021 and Beyond," ABA Environmental & Energy Litigation, Mass Torts and Products Liability Committees' Joint CLE Seminar (January 2021) 
• Moderator, "Impacts of COVID-19 on Federal and State Enforcement Actions and Clean-Ups: Force Majeure in the COVID Era," ABA Environmental & Energy Litigation, Mass Torts and Products Liability Committees' Joint CLE Seminar (January 2021) 
• Speaker and Moderator, "Groundwater as a Resource and Emerging Contaminants," 2017 Environmental Law Conference at Yosemite, California State Bar Environmental Law Section (October 2017)
• Speaker and Organizer, "Private Enforcement of Environmental Law: Key Developments, Trends and Tactics," California State Bar Environmental Law Section (May 2016)
• Moderator, "Report from the Paris Climate Change Conference: Decisions Reached, Open Issues and the Path Forward," California State Bar Environmental Law Section (April 2016)
• Speaker, "Strategies for Managing Complex Environmental Matters," Los Angeles County Bar Association, Spring Environmental Law Symposium (March 2015) 
• Speaker, “Environmental Due Diligence: What Really Matters,” California State Bar Real Estate Section Retreat (May 2015)
• Speaker, “Impacts of the U.S. Supreme Court's Ruling in CTS Corp. v. Waldburger on CERCLA’s Preemption of State Limitations Periods for Property and Personal Injury Claims,” Los Angeles County Bar Association (August 2014)
• Speaker, "California's Revised Industrial Stormwater Regulations," Los Angeles County Bar Association (December 2013)
• Speaker, “CERCLA's Mid-Life Crisis: How Best to Navigate Cost Recovery Actions,” 2013 Environmental Law Conference at Yosemite, California State Bar Environmental Law Section (October 2013)
• Speaker and Moderator, “Lessons Learned From the Deepwater Horizon Oil Spill,” 2011 Fall Environmental Law Symposium, Los Angeles County Bar Association Environmental Law Section (March 2011)
• Chair, “The Greening of California: Achieving Green Goals in a Time of Limited Financial Resources,” 2011 Spring Super Symposium, Los Angeles County Bar Association Environmental Law Section (March 2011)
• Speaker, “Greenhouse Gases: Cap and Trade, Regulatory Strategies, and Impacts on Our Economy and Environment,” Los Angeles County Bar Association (April 2011)
• Speaker, “Effective Opening Statements and Closing Arguments,” 2005 Environmental Trial Academy, California State Bar Association
• Speaker, “Seminar with Complex Court Judges and Selected Counsel Concerning Creative Techniques and Complex Case Management for Trials and Fact-Finding,” Los Angeles County Bar Association Litigation Section (2002)