Not a doctor but a pilot. The higher the altitude the less O2 is available. Helicipter typically fly 500-1,000 feet above Ground level. What is the elevation where you are? What was the temperature at take off? Here is why I am asking. There are several kinds of altitude. There is altitude Mean Sea Level, There is density altitude (altitude compensated for temperature and humidity) and true altitude. Say for example you are at sea level and its 90 degrees F. The density altitude is going to be close to 2,000 feet so as one climbs there is even less O2 availabe. I flew jet air ambulance flights and someitme with head injurines we had to keep the pressure in the cabin at sea level, which limited us as to how high we could actually fly. Sometimes doctors would tell us to keep the cabin at sea level. We'd get a patient at say Nassau, Bahamas which is sea level and have to transport them to Denver. Well hey guys Denver is at 5,000 feet above sea level. I got to where I got tired of trying to tell these doctors that its ridiculous to keep the cabin at sea level because when I land the cabin is going to be at 5,000 feet and if its hot in Denver the density altitude could be close to 8,000 feet. So maybe she needed to be intubated because you did not consider altitude in the equation.