Con Pilot,
Excellent point barit1, if in fact true, the posters here that are blaming the Legacy pilots for the accident for not changing their FL without ATC approval are proved totally wrong or Brazilians pilot would have been being violated by every country in the world.
No Con Pilot, NTSB/CENIPA is blaming the pilots, besides transponder issue, for not requesting an ammended clearance when they received a clearly incorrect (FL370 in UZ6) and incomplete clearance (CRAFT: Clearance limit, route, altitude, frequency, transponder).