Though they train for crisis situations, it is not fair to expect miracles or perfection from those who respond to 911 emergencies. They aren't doctors or rolling hospitals. They must make quick decisions under chaotic or even hostile circumstances.
Maryland law shields first responders, EMTs, paramedics and ambulance drivers from liability for bad outcomes of good faith efforts to help those in distress. But emergency personnel and their employers may be legally accountable for injury or death when they are reckless with protocols or derelict in their duty.