John Mather

Practice Areas

John Mather is a partner at DMG Advocates LLP.

John has a well-earned reputation as a smart, tough and practical litigator. John is a trusted advisor to business executives, in-house counsel, judges and government agencies.

John is adept on his feet in any setting: his favourite place to be is in court or a hearing room. As a litigator, John regularly appears before the Ontario Superior Court and Court of Appeal. He has acted in numerous domestic and international arbitrations, including in New York and Riyadh, Saudi Arabia. John also represents clients responding to investigations and proceedings before various regulatory and administrative bodies.

John’s commercial litigation work focuses on contractual disputes, product liability, class actions, securities and shareholder claims, commercial real estate, franchise and automobile dealer claims, procurement litigation, and media and defamation.

John also acts on urgent matters involving fraud, including successfully obtaining Mareva orders and other extraordinary relief.

John’s public litigation work focuses on public inquiries, regulatory or government investigations and defence of regulatory proceedings.

In 2022-2023, John served as Commission Counsel to Justice Rouleau of the Ontario Court of Appeal at the public inquiry investigating the federal government’s invocation of the Emergencies Act in response to the Freedom Convoy protests in January/February 2022. From 2019-2022, John acted as Associate Commission Counsel to then-Associate Chief Justice of Ontario Frank Marrocco at the Collingwood Judicial Inquiry, an extensive public investigation into alleged conflicts of interest and other concerns surrounding two major transactions by the Town of Collingwood.

Professional Memberships

John is a member of the Advocates Society and the International Association of Defence Counsel.

Clients

John's clients include leading automotive manufacturers, multi-national restaurant franchisors, government agencies, judicial officals, high net worth family businesses and investors, and international businesses operating in Canada.

Work Highlights

Select experience:

Wittal v. Ford Motor Company (2024): Lead counsel on succesful defence to application to certify a product liability class action.

Confidential Private Arbitration (2017-Present): Lead counsel to multinational restaurant franchisors regarding ongoing dispute with co-owner of large commercial real estate project.

Confidential NADAP Arbitration (2023): Lead counsel in a successful defence of an automotive manufacturer in claim brought by a dealer.

Confidential Safe Sport Arbitration (2023): Successfully defended a sports club in response to multiple safe sport allegations.

Heywood v. Pleterski (2022): Obtained Mareva order against Aiden Pleterski, the self-described “Crypto King”.

Darvish-Kazem v. Pazkaz Enterprises Inc., 2022 ONSC 1667: Successful defence of an oppression application.

Private Settlement (2021): Settled a claim of specific performance for payment of cryptocurrency under a services contract.

Trade Finance Solutions Inc. v. Equinox Global Limited, 2018 ONCA 12, overturning 2016 ONSC 7988: Successful appeal to enforce an arbitration clause.

Private Arbitration (2017-2018): Counsel to successful respondent in dispute regarding termination of a mining contract in Saudi Arabia.

9646035 Canada Ltd. v. Kristine Hill, 2017 ONSC 5252: Successful contempt of court motion.

9646035 Canada Ltd. v. Kristine Hill, 2017 ONSC 5453: Successful trespassing injunction.

Campisi v. Ontario, 2017 ONSC 2884: Opposing constitutional challenge to Insurance Act.

King v Giardina, 2017 ONSC 1588: Successful motion to stay action for want of jurisdiction.

U.S. Steel Canada Inc. (Re), 2016 ONCA 662: Successful defence of appeal confirming that doctrine of equitable subordination does not apply under CCAA.

U.S. Steel Canada Inc. (Re), 2016 ONCA 68: Successful defence of an appeal for disclosure of agreement with Industry Canada that was protected by settlement privilege.

Expert in these Jurisdictions

Ontario

Education