An Oak Lawn hospital dismissed from a wrongful-death lawsuit is back in court after a state appeals panel Monday found that questions remain whether an independent doctor acted as an apparent agent of the hospital.The 1st District Appellate Court found it was reasonable for plaintiff Natalie Hammer to assume Dr. Mary Jane Barth was acting on behalf of Advocate Christ Hospital when she performed a number of operations on her husband, Jerry Hammer, who died in 2010.Hammer sued Advocate, Barth and Barth’s employer …