This is fact:
The planes was close to an area of intense CB and TS activity.
Very few people has dared inside a TS, but almost every pilot have seen pictures of what happen to a plane that had ventured inside a Thunder Storm.
The selector of bright/intensity of the WX in the ND of the A330/340 sometimes brings to confusion. How many times an A320/330/340 pilots knows that his radar is ON, but he is unable to see anything in the ND because the WX bright is at the minimum intensity and he didnt notice.
Normaly the big selector must by related to the screen and the small one to the WX presentation. In the Airbus the small selector is related to the ND and the big one to the WX presentation. And normaly the big selector moves the small one, because this selectors are switched in the Airbus, this is not the case in these planes.