Only 3/5 hospitals said they would "limit or eliminate" the medical costs. So not only have all the hospitals not eliminated the medical costs, but for most patients the costs have been limited, not eliminated. Healthcare includes the permanent care that some now require after suffering permanent injury from shooting wounds. It also goes towards funeral costs for those killed in the shooting, which average around $7000 based off of most sources In addition, it is important to provide sufficient ongoing psychiatric care for those affected.
http://whatculture.com/film/the-dark-knight-rises-shooting-in-colorado-a-call-for-aid.php
http://capsules.kaiserhealthnews.org/index.php/2012/07/health-coverage-a-new-part-of-the-conversation-after-tragedy/
http://whatculture.com/film/the-dark-knight-rises-shooting-in-colorado-a-call-for-aid.php