As far as I know the Legacy pilots had originally a written plan for the flight from Sao Jose to Manaus. Sao Jose-Brasilia 370, Brasilia to somewhere on the way to Manaus 360, then climb to 380 to end the trip in Manaus. But after leaving Sao Jose the controller there said to them to go to Manaus at 370. Of course they changed their plan.
Marcio,
Do you any document citing it ? I would like to take a look.
Probably the ATC told then to go at FL370
UNTIL MANAUS. If that really happened than we have ATC again having an important role in this accident