Where an employee could seek back pay for unpaid medical leave that they were forced to take due to hostile work environment, the lower court order was affirmed in part and reversed in part.The 7th U.S. Circuit Court of Appeals affirmed in part and reversed in part a decision by Chief U.S. District Judge Ruben Castillo.Costco is a warehouse club open to members who pay an annual fee. In 2009, Dawn Suppo began working at Costco’s store in north suburban Glenview as a seasonal part-time employee; in May 2010, she …