In what the Washington Post called a “surprise” decision, the International Trade Commission on Friday struck down a planned 300 percent tariff on narrow-body Canadian jetliners by Bombadier.

Behind the win: lawyers from Covington & Burling, who argued on behalf of Bombadier that the planes do not materially injure a U.S. industry—namely, The Boeing Co.

“The unanimous decision in our favor was particularly rewarding,” said Covington partner Peter Lichtenbaum. “Trade cases are always challenging to defend, and this case was even more challenging because of the unique and unprecedented issues associated with multibillion dollar aircraft programs that operate over many decades. Covington's team sought to focus the ITC on the implications of these issues.”

The Covington team was led by partners Shara Aranoff, Brian Smith, and William Isasi, and included Maureen Browne, John Veroneau, James M. Smith, Victor Ban, Marta Cook, Ruchi Gill, Doron Hindin, Minwoo Kim, Ingrid Price, Isaac Belfer, Vivian Choi, Shelby Anderson, and Elena Postnikova.

The Post reported that the decision removes a major sticking point as the U.S. and Canada seek to renegotiate NAFTA.

The ITC decision was a victory as well for the government of Canada, represented by Steptoe & Johnson LLP, and Delta Airlines, which had struck a deal with Bombadier to buy 75 of its CS100 planes. Delta turned to counsel from Dentons.

On the losing side: Boeing, represented by Wilmer Cutler Pickering Hale and Dorr lawyers including Robert Novick, the firm's co-managing partner and former a general counsel for the Office of the U.S. Trade Representative.