The following are some of his notable clients and matters.
- California Franchise Tax Board. Mr. Guy represents the California Franchise Tax Board in bankruptcy litigation across the United States.
- Commonwealth of Pennsylvania. Mr. Guy represents the Commonwealth in litigation concerning the Master Settlement Agreement with various tobacco companies and in 2014 was successful in reversing an arbitration award against the Commonwealth.
- Garlock Sealing Technologies. Mr. Guy represents the court-appointed future claimants' representative in complex litigation involving the debtor Garlock Sealing.
- Delmarva Power & Light. Mr. Guy represented Delmarva Power & Light in connection with a proposed offshore wind power purchase agreement, and certain onshore wind contracts, the first for any Delaware utility.
- Federal Mogul. Mr. Guy represented Cooper Industries, a principal creditor and holder of an indemnity claim of over $450 million, in connection with the restructuring of Federal Mogul, a worldwide manufacturer and distributor of automotive and other products.
- Mirant. Mr. Guy represented Potomac Electric Power Company (Pepco) in complex, cutting-edge litigation concerning the ability of Mirant, a debtor power company, to reject electric power contracts. Pepco prevailed through three appeals against Mirant before the United States Court of Appeals for the Fifth Circuit and extensive litigation before the bankruptcy court, the district court and FERC, obtaining a precedent-setting ruling against Mirant that requires bankruptcy courts to take the public interest into consideration when determining whether a debtor may reject electric power contracts. In a subsequent settlement, Mirant paid Pepco in excess of $720 million, including all of its legal fees.
- NRG Energy. Mr. Guy represented Niagara Mohawk Power Corporation and various affiliates as creditors/utility providers and as a member of the creditors' committee in the NRG Energy, Inc. Chapter 11. Mr. Guy was lead counsel for the negotiation of a pass-through arrangement whereby his clients' receiving a full recovery.
- USGen New England, Inc. Mr. Guy represented National Grid USA and related companies in litigation relating to USGen's asset sales. Jonathan's clients' claims, which exceeded $200 million, were paid in full.
Mr. Guy, the partner in charge of pro bono for Orrick's Washington, D.C., office, has long been active in numerous pro bono matters, including the following.
- NAACP v. Maryland State Police and Wilkins v. Maryland State Police, a ground-breaking racial profiling case, which resulted in comprehensive reform of policies and procedures of the Maryland State Police.
- Successful challenge of a proposed federal law seeking to remove patients at St. Elizabeth's Hospital, D.C., found not guilty by reason of insanity to remote federal facilities across the country.
- Successful appeals from involuntary military discharges under the Don't Ask Don't Tell policy.
- Successful appeals on behalf of African-American farmers in Pigford v. Venemana, class-action case regarding race discrimination in the award of benefits and subsidies by the U.S. Department of Agriculture.
- Advisor to the bipartisan Presidential Commission for the National Museum for African American History.
- Successfully representing the American Civil Liberties Union of Maryland in an eminent domain/freedom of information case before the Maryland Court of Appeals.
- Successfully representing an Ocean City boardwalk musician in a free speech case.
- Successfully representing various applicants of disability benefits, individuals in various immigration proceedings, and victims of domestic abuse.