The flash of light contributes to the theory that an explosion is what brought down AF447, which was carrying 228 people from Rio de Janeiro to Paris.”
There is absolutely no evidence in the flight data to support this theory. Where was this aircraft that they could have possibly seen them?
Check out this animation that shows the other aircraft in the area deviating around the weather that helped bring AF447 down. (note the animation does not load with Chrome - works good in IE
Flight Paths of Flight AF 447 and of the flights that crossed the zone around the same time