When DeLuca is in the ER after being beaten up, Maggie volunteers to call and tell his mother about his injuries saying, "I'll call her. She knows me." However later on in S15:E4 while DeLuca talks to Max (a patient's son) about his mom, he tells Max that his own mother died when he was in college. There's no way Maggie could know her if she died while DeLuca was in college.