The court told them all state employees would be limited to pay at the federal minimum wage rate of $5.15 per hour NOT the California minimum wage of $6.75. I think you read that backwards.
The court also interpreted a previous federal court ruling requiring payments to state workers under the Fair Labor Standards Act to mean the state minimum wage, $6.75 an hour.
Another parallel article on this issue stated that wages would be paid at the federal rate not the state rate. I suspect Connell et al are angling for the state rate to reduce the howls from state employees.