If you have to make a schedule change after someone returns from, be sure you have legitimate business reasons.
Recent case: Ernestine worked full-time for Columbia Memorial and part-time for another medical facility. Her shift included early evenings to accommodate the second job. Then she went onleave. When she returned, she learned that she would no longer have the later shift.
She sued, alleging retaliation for taking FMLA leave. The court said that the leave change timing was theoretically a problem. However, the hospital could show it made the change so it always had a supervisor available to help Ernestine, who had lifting restrictions. Supervisors only worked during the day. The case was dismissed. (Welch v. Columbia Memorial, No. 1:13-CV-1079, ND NY, 2015)