WASHINGTON—Arbitrators have issued their final report into U.S. complaints about how Canada is interpreting North American trade rules around dairy imports—and both countries are claiming victory. U.S. Trade Representative Katherine Tai formally requested a dispute settlement panel last May to examine allegations from American producers that Canada is denying them fair access to the Canadian market. That panel, established under the U.S.-Mexico-Canada Agreement’s dispute-resolution system, says clearly that Canada’s practices are “inconsistent” with the commitments spelled out in the trade deal. Tai’s office says it has “prevailed” in the dispute, which accused Canada of unfairly favouring Canadian processors, effectively denying U.S. farmers their fair share of the supply-managed Canadian market. In their own statement, however, Trade Minister Mary Ng and Agriculture Minister Marie-Claude Bibeau say the ruling is “overwhelmingly in favour” of Canada’s dairy industry. The Canadian statement acknowledges the report’s findings about quotas for dairy processors, but offers no …