Having recently experienced severe probe icing while avoiding CB at high altitude I can understand how the AF crew would be struggling to understand what was happening and might have been distracted from their avoidance of active CB tops. I would be interested to know more about the A330 radar control panel as fitted on this aircraft. Does it have an auto tilt function? If not, failure to reset the tilt manually to a cruise setting at top of climb might have meant that CB radar returns were not seen or correctly presented. An inadvertent CB penetration while coping with probe icing problems could easily lead to a big upset.