A federal appeals court delivered a surprising twist in the epic series of legal battles between Chevron Corp. and residents of the Ecuadorean rain forest — who won a $9 billion judgment against the oil company for polluting their home — when it reversed a lower court’s order that gave Chevron the right to take the deposition of Philadelphia attorney Joseph C. Kohn of Kohn Swift & Graf.

Chevron — which was hit with a $9 billion judgment in Ecuador — has been waging battles on three fronts to undo the judgment and won an injunction from a New York federal judge that has barred the plaintiffs from enforcing it.