By an 8-to-1 vote, the high court ruled against unionized truck drivers who walked off the job, leaving their trucks loaded with wet concrete, but it preserved the rights of workers to time their strikes for maximum effect.

“Virtually every strike is based on timing that will hurt the employer,” said Stanford Law School professor William Gould, a former chairman of the National Labor Relations Board, and there was “great concern that the court would rule broadly to limit the rights of strikers. “But that didn’t happen,” he noted in an interview with NPR.