The U.S. Supreme Court appeared open to the idea Tuesday that some courts have been too deferential to the National Labor Relations Board in unfair labor practice cases, as justices seemed to lean in favor of Starbucks in litigation over fired workers who had been trying to start a union.

In Starbucks Corp. v. M. Kathleen McKinney, the high court is considering the coffee giant’s appeal of a ruling for seven fired baristas who had been engaged in a campaign to unionize their coffee shop in Memphis, Tennessee. The case deals with the proper test courts should impose before hitting employers with injunctions pending an NLRB investigation into whether they violated labor laws.