I believe that the flight crews forward planning carried out in Rio was not as it should have been.
Having seen the weather forecast for the flight and the problems that could be encountered flying in this area, a much clearer command and control structure should have been emphasized by the Captain of the aircraft. Especially concerning Command & Control of the aeroplane when he was absent from the Flightdeck.
Which brings me to another major issue I have, all the flight deck crew knew they were flying into weather problems. If they also knew that aircraft ahead of them had made course and altitude alterations to go round these serious weather issues, why was the same decision not made by this crew?
A lot of the problems here as far as I am concerned come down to poor forward planning and management by an experienced Captain in Air France.