They missed the infection for the first 2 days. At which point they administered the wrong antibiotic protocol which failed to treat the infection and allowed the membrane rupture to be prolonged for an additional 2 days knowing that this can lead to sepsis at which point the fetus became infected and she became septic. Furthermore they didn't change the antibiotic regime until she was already in septic shock and only now did the miscarriage take place. Notice that despite the fetus being out she died. That's because the real failure is delaying the treatment of sepsis. That's what happens when they don't want to whip out the piptazo until they needed the ventilator.