Can't they fly around storms - just to be extra safe? This may delay the flight - but isn't it better than risking getting hit by lightening, even if the plane is designed to take a hit... It can't be much fun to be a nervous flier and run a gauntlet of lightning!
They're required to remain 20 nautical miles clear of severe thunderstorms with intense echos (I think today's new classification is extreme). Pilots should also go around an entire area if storm coverage is 6/10 or greater! These are US flying rules, I'm not sure how much applies to ICAO standards and oceanic flying. I also have no idea what was painted on their airborne radar, or what else could have happened. When I was flying from Chicago to Denver on an MD-80 last month, we flew through a moderate thunderstorm. We got tossed like a salad. I'm a pilot and I was very uncomfortable cause the thoughts running through my head are what's on my mind now: Premature failure, metal fatigue, complications to flight arising from compromising situation.