The Supreme Court appeared skeptical on Monday of a Minnesota school district’s argument that students with disabilities must prove their school acted in “bad faith” in failing to provide adequate accommodations in order to prove discrimination.

A family who had sued the district, the Osseo Area School District near Minneapolis, argued that federal law required merely that the school display “deliberate indifference,” a lower standard.

The two sides had argued in front of lower courts over the legal standard in schools. But in recent court filings, the school district argued that the higher standard could apply broadly to all sorts of disability rights claims under the Rehabilitation Act and the Americans with Disabilities Act.

That unnerved some disability rights groups, who warned that if the court accepted the school district’s argument, the higher “bad faith” standard could make it much harder for Americans with disabilities to successfully bring court challenges.

The school district’s position led to an unusually tense oral argument, with lawyers for the family and the federal government arguing that the district had improperly shifted its position after the justices had agreed to hear the case. The lawyer for the school district rejected those claims, going so far as to suggest that her opponents were lying, an accusation that prompted a rebuke from one of the justices.

The case, A.J.T. v. Osseo Area Schools, No. 24-249, stemmed from a dispute over whether the Minnesota school district provided reasonable accommodations for Ava Tharpe, a teenage girl with severe epilepsy that made it difficult for her to attend school during normal hours.