(Reuters) - Native American tribes scored a legal victory in their long-fought case against the Dakota Access pipeline, but it is unclear whether a judge will actually stop oil from flowing, even temporarily, when the parties meet again next week.

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U.S. District Judge James Boasberg in Washington on Wednesday ruled that the Army Corps of Engineers, in its environmental review of the Dakota Access line, did not fully consider the pipeline’s impact on the hunting, fishing and environmental justice rights of the Standing Rock Sioux Tribe. The tribe has been fighting the line for more than a year.

Legal experts on Thursday said Boasberg has quite a bit of leeway with his decision, depending on what he deems are the environmental impacts of allowing oil to keep flowing.

“Under U.S. Supreme Court precedent he should apply the traditional injunction test to determine exactly what may occur - or not - during additional environmental analysis,” said Zeke Williams, managing director of the energy and natural resources practice at Lewis Bess Williams & Weese in Denver.

The parties, including pipeline owner Energy Transfer Partners Inc, are scheduled to reconvene on Wednesday. The Standing Rock Sioux and Cheyenne River Sioux want the judge to stop the pipeline flow when he considers the possibility of additional environmental review.

“Our position has always been that until they can do this correctly, the pipeline shouldn’t be operating,” said Earthjustice attorney Jan Hasselman, who represents the Standing Rock Sioux.

In a statement, ETP said pipeline operations will continue as the “limited” process unfolds to review the issues raised. “Dakota Access believes the record supports the fact that the Corps properly evaluated” those issues, said ETP spokeswoman Vicki Granado.

The $3.8 billion Dakota line began service at the beginning of the month, with commitments to ship 520,000 barrels of crude a day from North Dakota’s Bakken region. The line was delayed during months of protests on federal land in North Dakota and as a legal battle played out in Washington. Two of the tribe’s earlier arguments had been rejected by the same judge.

The 1,170-mile (1,880 km) line had been a long-desired project for Bakken producers, but met heavy resistance from the tribes over concerns about water supply and sacred lands.

Deborah Ann Sivas, director of the Environmental and Natural Resources Law & Policy Program at Stanford Law School, said the normal remedy under the National Environmental Policy Act would be to stop operations during the review period.

She said NEPA’s purpose is to “ensure that decisionmakers are informed about project impacts, alternatives, and mitigation before they allow a project to go forward.”

The first shipment of Bakken crude to Asia left port in April, and more was expected as U.S. production continues to rise. Cash traders on Thursday said the legal battle at this moment is not an issue, because operations have not been affected.

“This ruling was a bit of a curve ball given the judge’s prior orders,” said U.S. Representative Kevin Cramer, a Republican from North Dakota who supports the pipeline. He said he did not believe operations would be halted during review.

“(The judge) seems to be sending a message that consultation needs to be considered and documented better in future cases like this,” he told Reuters.

ETP shares were down 2.8 percent at $19.20 on Thursday afternoon.