If you RTFA, the flight took place at Flight Level 400 (i.e. 40,000 ft). This is well within Class A airspace (http://en.wikipedia.org/wiki/Airspace_class_(Uni
t ed_States)#Class_A) which means that there are substantial requirements as to which pilots and aircraft may fly (IFR certification, etc) and that all flight paths are dictated by ATC. The pilots could have asked for a certain route ahead of time, but it's more likely that they got special permission from ATC.