BOAC, I don't believe they knowingly and purposefully flew into a meso-convective complex with cells that were overshooting to FL 520 or 560.
- so carefully worded I understand you do believe they did fly into one at 350. So be it.
The 'difference' you query could be explained by the fact that they were two different crews who 'read' the situation differently. Also in 10 minutes a cell can move quite a distance in relation to an avoid distance of 20 miles or so, so the question is not what 449 or IB did, but what 447 did. If I had 2 Drachma for all the different interpretations of 'weather' I have seen in my career I would be able to rescue Greece from bankruptcy.
As you say, the information from the other flights (and 447) is not complete. We do not know, for example what they saw or decided weather-wise after the CVR 'left 12 degrees'.
I do not understand why you do not accept that at the moment the accident APPEARS to have been primarily triggered by pitot icing in cloud - not a CB. Cloud is pretty difficult to avoid at night.