The U.S. Supreme Court ruled unanimously Tuesday that a Texas federal court's judgment in a baby food heavy metals suit against Hain Celestial Group and Whole Foods must be vacated and the case remanded to state court, finding the erroneous dismissal of non-diverse defendant Whole Foods tainted federal jurisdiction from the start.

Justice Clarence Thomas wrote for the court that when an appellate court determines a non-diverse party (here Whole Foods, Texas-based) was wrongly dismissed from a removed case, the final federal decision cannot stand — even if the remaining parties are diverse. The ruling ends Hain's bid to keep the Palmquist family's suit in federal court.

The Palmquists sued in Texas state court, alleging Hain's Earth's Best Organic baby food — sold at Whole Foods — contained unsafe levels of arsenic, lead, cadmium, and mercury, causing their son Ethan's physical and mental health issues. Hain removed to federal court, arguing improper joinder of Whole Foods (fraudulent to defeat diversity). A Texas federal judge dismissed claims against Whole Foods and later granted summary judgment to Hain on causation.

The Fifth Circuit reversed the joinder ruling but affirmed the federal judgment. SCOTUS granted certiorari and reversed, holding the improper dismissal of Whole Foods meant the case never belonged in federal court. Rule 21 (adding/dismissing parties on just terms) cannot override a plaintiff's right to choose state forum by properly joining a non-diverse defendant.

"The Palmquists exercised their right to choose a state forum by purposefully and properly joining a nondiverse defendant against whom they could not proceed in federal court, and diligently asserted that right by promptly moving to remand the case to state court," the court wrote. "Rule 21 does not permit a court or a defendant to override their choice in these circumstances."

During November oral arguments, Justice Sonia Sotomayor pressed Hain's counsel on the "tactical advantage" of state court, noting parties fight removal precisely because forums matter. Hain argued no prejudice in federal trial; the court disagreed, emphasizing plaintiffs' forum choice.

The case returns to Texas state court, where the Palmquists may pursue claims against both Hain and Whole Foods, potentially developing evidence on misrepresentations of product quality that the federal case never reached.

Hain is represented by Sarah E. Harrington of Covington & Burling LLP. The Palmquists are represented by Russell S. Post of Beck Redden LLP.

The decision strengthens plaintiffs' ability to keep properly joined cases in state court and limits defendants' removal tactics in product liability suits — a significant win for forum choice in consumer safety litigation amid ongoing heavy metals concerns in baby food.