The whole concept of "trauma medicine" and "trauma center" was invented in Maryland - at the University of MD medical center in Baltimore - by Dr. R. Adams Cowley - "The "Father" of Shock Trauma Medicine.
See:
http://www.arlingtoncemetery.com/racowley.htm From the site:
It had been while Dr Cowley was an Army surgeon just after World War II in Europe that he first began developing his ideas about quick treatment of the seriously injured people. Dr Cowley developed the idea that there is a "golden hour" just after a serious injury, during which prompt and coordinated medical treatment can save lives. He began with a two-bed research unit at the University of Maryland Hospital in 1961, and worked to build his dream, living to see the opening in 1989 of the eight-story Shock-Trauma Center in Baltimore, which was named for him.
As you are aware, such centers are now wide-spread. I suspect that the whole concept of "EMT" can be traced back to the early trauma centers. It appears that the mother just made a mistake. As "developed" as the MD/DC/VA area is, it would not have been long before either EMT's or a med-evac helicopter would have been on scene. Like minutes.